field.h

#ifndef FIELD_INCLUDED
#define FIELD_INCLUDED

/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include "mysqld.h"                             /* system_charset_info */
#include "table.h"                              /* TABLE */
#include "sql_string.h"                         /* String */
#include "my_decimal.h"                         /* my_decimal */
#include "sql_error.h"                          /* Sql_condition */
#include "mysql_version.h"                      /* FRM_VER */

/*

Field class hierarchy


Field (abstract)
|
+--Field_bit
|  +--Field_bit_as_char
|  
+--Field_num (abstract)
|  |  +--Field_real (asbstract)
|  |     +--Field_decimal
|  |     +--Field_float
|  |     +--Field_double
|  |
|  +--Field_new_decimal
|  +--Field_short
|  +--Field_medium
|  +--Field_long
|  +--Field_longlong
|  +--Field_tiny
|     +--Field_year
|
+--Field_str (abstract)
|  +--Field_longstr
|  |  +--Field_string
|  |  +--Field_varstring
|  |  +--Field_blob
|  |     +--Field_geom
|  |
|  +--Field_null
|  +--Field_enum
|     +--Field_set
|
+--Field_temporal (abstract)
   +--Field_time_common (abstract)
   |  +--Field_time
   |  +--Field_timef
   |
   +--Field_temporal_with_date (abstract)
      +--Field_newdate
      +--Field_temporal_with_date_and_time (abstract)
         +--Field_timestamp
         +--Field_datetime
         +--Field_temporal_with_date_and_timef (abstract)
            +--Field_timestampf
            +--Field_datetimef
*/


class Send_field;
class Protocol;
class Create_field;
class Relay_log_info;
class Field;

enum enum_check_fields
{
  CHECK_FIELD_IGNORE,
  CHECK_FIELD_WARN,
  CHECK_FIELD_ERROR_FOR_NULL
};


enum Derivation
{
  DERIVATION_IGNORABLE= 6,
  DERIVATION_NUMERIC= 5,
  DERIVATION_COERCIBLE= 4,
  DERIVATION_SYSCONST= 3,
  DERIVATION_IMPLICIT= 2,
  DERIVATION_NONE= 1,
  DERIVATION_EXPLICIT= 0
};

enum type_conversion_status
{
  TYPE_OK= 0,
  TYPE_NOTE_TIME_TRUNCATED,
  TYPE_WARN_OUT_OF_RANGE,
  TYPE_NOTE_TRUNCATED,
  TYPE_WARN_TRUNCATED,
  TYPE_ERR_NULL_CONSTRAINT_VIOLATION,
  TYPE_ERR_BAD_VALUE,
  TYPE_ERR_OOM
};


#define STORAGE_TYPE_MASK 7
#define COLUMN_FORMAT_MASK 7
#define COLUMN_FORMAT_SHIFT 3

#define my_charset_numeric      my_charset_latin1
#define MY_REPERTOIRE_NUMERIC   MY_REPERTOIRE_ASCII

struct st_cache_field;
type_conversion_status field_conv(Field *to,Field *from);

inline uint get_enum_pack_length(int elements)
{
  return elements < 256 ? 1 : 2;
}

inline uint get_set_pack_length(int elements)
{
  uint len= (elements + 7) / 8;
  return len > 4 ? 8 : len;
}

inline type_conversion_status
decimal_err_to_type_conv_status(int dec_error)
{
  if (dec_error & E_DEC_OOM)
    return TYPE_ERR_OOM;

  if (dec_error & (E_DEC_DIV_ZERO | E_DEC_BAD_NUM))
    return TYPE_ERR_BAD_VALUE;

  if (dec_error & E_DEC_TRUNCATED)
    return TYPE_NOTE_TRUNCATED;

  if (dec_error & E_DEC_OVERFLOW)
    return TYPE_WARN_OUT_OF_RANGE;

  if (dec_error == E_DEC_OK)
    return TYPE_OK;

  // impossible
  DBUG_ASSERT(false);
  return TYPE_ERR_BAD_VALUE;
}

inline type_conversion_status
time_warning_to_type_conversion_status(const int warn)
{
  if (warn & MYSQL_TIME_NOTE_TRUNCATED)
    return TYPE_NOTE_TIME_TRUNCATED;

  if (warn & MYSQL_TIME_WARN_OUT_OF_RANGE)
    return TYPE_WARN_OUT_OF_RANGE;

  if (warn & MYSQL_TIME_WARN_TRUNCATED)
    return TYPE_NOTE_TRUNCATED;

  if (warn & (MYSQL_TIME_WARN_ZERO_DATE | MYSQL_TIME_WARN_ZERO_IN_DATE))
    return TYPE_ERR_BAD_VALUE;

  if (warn & MYSQL_TIME_WARN_INVALID_TIMESTAMP)
    // date was fine but pointed to daylight saving time switch gap
    return TYPE_OK;

  DBUG_ASSERT(!warn);
  return TYPE_OK;
}

#define ASSERT_COLUMN_MARKED_FOR_READ \
DBUG_ASSERT(!table || (!table->read_set || \
                       bitmap_is_set(table->read_set, field_index)))
#define ASSERT_COLUMN_MARKED_FOR_WRITE \
DBUG_ASSERT(!table || (!table->write_set || \
                       bitmap_is_set(table->write_set, field_index)))


inline bool is_temporal_type(enum_field_types type)
{
  switch (type)
  {
  case MYSQL_TYPE_TIME:
  case MYSQL_TYPE_DATETIME:
  case MYSQL_TYPE_TIMESTAMP:
  case MYSQL_TYPE_DATE:
  case MYSQL_TYPE_NEWDATE:
    return true;
  default:
    return false;
  }
}


inline bool is_temporal_real_type(enum_field_types type)
{
  switch (type)
  {
  case MYSQL_TYPE_TIME2:
  case MYSQL_TYPE_TIMESTAMP2:
  case MYSQL_TYPE_DATETIME2:
    return true;
  default:
    return is_temporal_type(type);
  }
}


inline bool is_temporal_type_with_time(enum_field_types type)
{
  switch (type)
  {
  case MYSQL_TYPE_TIME:
  case MYSQL_TYPE_DATETIME:
  case MYSQL_TYPE_TIMESTAMP:
    return true;
  default:
    return false;
  }
}


inline bool is_temporal_type_with_date(enum_field_types type)
{
  switch (type)
  {
  case MYSQL_TYPE_DATE:
  case MYSQL_TYPE_DATETIME:
  case MYSQL_TYPE_TIMESTAMP:
    return true;
  default:
    return false;
  }
}


inline bool is_temporal_type_with_date_and_time(enum_field_types type)
{
  switch (type)
  {
  case MYSQL_TYPE_DATETIME:
  case MYSQL_TYPE_TIMESTAMP:
    return true;
  default:
    return false;
  }
}


inline bool real_type_with_now_as_default(enum_field_types type)
{
  return type == MYSQL_TYPE_TIMESTAMP || type == MYSQL_TYPE_TIMESTAMP2 ||
    type == MYSQL_TYPE_DATETIME || type == MYSQL_TYPE_DATETIME2;
}


inline bool real_type_with_now_on_update(enum_field_types type)
{
  return type == MYSQL_TYPE_TIMESTAMP || type == MYSQL_TYPE_TIMESTAMP2 ||
    type == MYSQL_TYPE_DATETIME || type == MYSQL_TYPE_DATETIME2;
}


inline bool is_timestamp_type(enum_field_types type)
{
  return type == MYSQL_TYPE_TIMESTAMP || type == MYSQL_TYPE_TIMESTAMP2;
}


inline enum_field_types real_type_to_type(enum_field_types real_type)
{
  switch (real_type)
  {
  case MYSQL_TYPE_TIME2:
    return MYSQL_TYPE_TIME;
  case MYSQL_TYPE_DATETIME2:
    return MYSQL_TYPE_DATETIME;
  case MYSQL_TYPE_TIMESTAMP2:
    return MYSQL_TYPE_TIMESTAMP;
  case MYSQL_TYPE_NEWDATE:
    return MYSQL_TYPE_DATE;
  /* Note: NEWDECIMAL is a type, not only a real_type */
  default: return real_type;
  }
}


template<bool Is_big_endian>
void copy_integer(uchar *to, int to_length,
                  const uchar* from, int from_length,
                  bool is_unsigned)
{
  if (Is_big_endian)
  {
    if (is_unsigned)
      to[0]= from[0];
    else
      to[0]= (char)(from[0] ^ 128); // Reverse the sign bit.
    memcpy(to + 1, from + 1, to_length - 1);
  }
  else
  {
    const int sign_byte= from[from_length - 1];
    if (is_unsigned)
      to[0]= sign_byte;
    else
      to[0]= static_cast<char>(sign_byte ^ 128); // Reverse the sign bit.
    for (int i= 1, j= from_length - 2; i < to_length; ++i, --j)
      to[i]= from[j];
  }
}


class Field
{
  Field(const Item &);                          /* Prevent use of these */
  void operator=(Field &);
public:

  bool has_insert_default_function() const
  {
    return unireg_check == TIMESTAMP_DN_FIELD ||
      unireg_check == TIMESTAMP_DNUN_FIELD;
  }

  bool has_update_default_function() const
  {
    return unireg_check == TIMESTAMP_UN_FIELD ||
      unireg_check == TIMESTAMP_DNUN_FIELD;
  }

  /* To do: inherit Sql_alloc and get these for free */
  static void *operator new(size_t size) throw ()
  { return sql_alloc(size); }
  static void *operator new(size_t size, MEM_ROOT *mem_root) throw () {
    return alloc_root(mem_root, size);
  }
  static void operator delete(void *ptr, MEM_ROOT *mem_root)
  { DBUG_ASSERT(false); /* never called */ }

  static void operator delete(void *ptr_arg, size_t size) throw()
  { TRASH(ptr_arg, size); }

  uchar         *ptr;                   // Position to field in record

protected:
  uchar         *null_ptr;

public:
  /*
    Note that you can use table->in_use as replacement for current_thd member 
    only inside of val_*() and store() members (e.g. you can't use it in cons)
  */
  TABLE *table;                                 // Pointer for table
  TABLE *orig_table;                            // Pointer to original table
  const char    **table_name, *field_name;
  LEX_STRING    comment;
  /* Field is part of the following keys */
  key_map key_start;                /* Keys that starts with this field */
  key_map part_of_key;              /* All keys that includes this field */
  key_map part_of_key_not_clustered;/* ^ but only for non-clustered keys */
  key_map part_of_sortkey;          /* ^ but only keys usable for sorting */
  /* 
    We use three additional unireg types for TIMESTAMP to overcome limitation 
    of current binary format of .frm file. We'd like to be able to support 
    NOW() as default and on update value for such fields but unable to hold 
    this info anywhere except unireg_check field. This issue will be resolved
    in more clean way with transition to new text based .frm format.
    See also comment for Field_timestamp::Field_timestamp().
  */
  enum utype  { NONE,DATE,SHIELD,NOEMPTY,CASEUP,PNR,BGNR,PGNR,YES,NO,REL,
                CHECK,EMPTY,UNKNOWN_FIELD,CASEDN,NEXT_NUMBER,INTERVAL_FIELD,
                BIT_FIELD, TIMESTAMP_OLD_FIELD, CAPITALIZE, BLOB_FIELD,
                TIMESTAMP_DN_FIELD, TIMESTAMP_UN_FIELD, TIMESTAMP_DNUN_FIELD};
  enum geometry_type
  {
    GEOM_GEOMETRY = 0, GEOM_POINT = 1, GEOM_LINESTRING = 2, GEOM_POLYGON = 3,
    GEOM_MULTIPOINT = 4, GEOM_MULTILINESTRING = 5, GEOM_MULTIPOLYGON = 6,
    GEOM_GEOMETRYCOLLECTION = 7
  };
  enum imagetype { itRAW, itMBR};

  utype         unireg_check;
  uint32        field_length;           // Length of field
  uint32        flags;
  uint16        field_index;            // field number in fields array
  uchar         null_bit;               // Bit used to test null bit
  bool is_created_from_null_item;

  Field(uchar *ptr_arg,uint32 length_arg,uchar *null_ptr_arg,
        uchar null_bit_arg, utype unireg_check_arg,
        const char *field_name_arg);
  virtual ~Field() {}

  /* Store functions returns 1 on overflow and -1 on fatal error */
  virtual type_conversion_status store(const char *to, uint length,
                                       const CHARSET_INFO *cs)=0;
  virtual type_conversion_status store(double nr)=0;
  virtual type_conversion_status store(longlong nr, bool unsigned_val)=0;
  virtual type_conversion_status store_packed(longlong nr)
  {
    return store(nr, 0);
  }
  virtual type_conversion_status store_decimal(const my_decimal *d)=0;
  virtual type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  type_conversion_status store_time(MYSQL_TIME *ltime)
  {
    return store_time(ltime, 0);
  }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *cs,
                               enum_check_fields check_level);
  virtual double val_real(void)=0;
  virtual longlong val_int(void)=0;
  virtual longlong val_time_temporal()
  {
    DBUG_ASSERT(0);
    return 0;
  }
  virtual longlong val_date_temporal()
  {
    DBUG_ASSERT(0);
    return 0;
  }
  longlong val_temporal_by_field_type()
  {
    // Return longlong TIME or DATETIME representation, depending on field type
    if (type() == MYSQL_TYPE_TIME)
      return val_time_temporal();
    DBUG_ASSERT(is_temporal_with_date());
    return val_date_temporal();
  }
  virtual my_decimal *val_decimal(my_decimal *)= 0;
  inline String *val_str(String *str) { return val_str(str, str); }
  /*
     val_str(buf1, buf2) gets two buffers and should use them as follows:
     if it needs a temp buffer to convert result to string - use buf1
       example Field_tiny::val_str()
     if the value exists as a string already - use buf2
       example Field_string::val_str()
     consequently, buf2 may be created as 'String buf;' - no memory
     will be allocated for it. buf1 will be allocated to hold a
     value if it's too small. Using allocated buffer for buf2 may result in
     an unnecessary free (and later, may be an alloc).
     This trickery is used to decrease a number of malloc calls.
  */
  virtual String *val_str(String*,String *)=0;
  String *val_int_as_str(String *val_buffer, my_bool unsigned_flag);
  /*
   str_needs_quotes() returns TRUE if the value returned by val_str() needs
   to be quoted when used in constructing an SQL query.
  */
  virtual bool str_needs_quotes() { return FALSE; }
  virtual Item_result result_type () const=0;
  virtual Item_result numeric_context_result_type() const
  {
    return result_type();
  }
  virtual Item_result cmp_type () const { return result_type(); }
  virtual Item_result cast_to_int_type () const { return result_type(); }
  static bool type_can_have_key_part(enum_field_types);
  static enum_field_types field_type_merge(enum_field_types, enum_field_types);
  static Item_result result_merge_type(enum_field_types);
  virtual bool eq(Field *field)
  {
    return (ptr == field->ptr && null_ptr == field->null_ptr &&
            null_bit == field->null_bit && field->type() == type());
  }
  virtual bool eq_def(Field *field);
  
  /*
    pack_length() returns size (in bytes) used to store field data in memory
    (i.e. it returns the maximum size of the field in a row of the table,
    which is located in RAM).
  */
  virtual uint32 pack_length() const { return (uint32) field_length; }

  /*
    pack_length_in_rec() returns size (in bytes) used to store field data on
    storage (i.e. it returns the maximal size of the field in a row of the
    table, which is located on disk).
  */
  virtual uint32 pack_length_in_rec() const { return pack_length(); }
  virtual bool compatible_field_size(uint metadata, Relay_log_info *rli,
                                     uint16 mflags, int *order);
  virtual uint pack_length_from_metadata(uint field_metadata)
  {
    DBUG_ENTER("Field::pack_length_from_metadata");
    DBUG_RETURN(field_metadata);
  }
  virtual uint row_pack_length() const { return 0; }
  virtual int save_field_metadata(uchar *first_byte)
  { return do_save_field_metadata(first_byte); }

  /*
    data_length() return the "real size" of the data in memory.
  */
  virtual uint32 data_length() { return pack_length(); }
  virtual uint32 sort_length() const { return pack_length(); }

  virtual uint32 max_data_length() const {
    return pack_length();
  };

  virtual type_conversion_status reset(void)
  {
    memset(ptr, 0, pack_length());
    return TYPE_OK;
  }
  virtual void reset_fields() {}
  virtual bool get_timestamp(struct timeval *tm, int *warnings);
  virtual void store_timestamp(const timeval *tm) { DBUG_ASSERT(false); }

  void store_timestamp(my_time_t sec)
  {
    struct timeval tm;
    tm.tv_sec= sec;
    tm.tv_usec= 0;
    store_timestamp(&tm);
  }
  virtual void set_default()
  {
    if (has_insert_default_function())
    {
      evaluate_insert_default_function();
      return;
    }

    my_ptrdiff_t l_offset= (my_ptrdiff_t) (table->s->default_values -
                                          table->record[0]);
    memcpy(ptr, ptr + l_offset, pack_length());
    if (real_maybe_null())
      *null_ptr= ((*null_ptr & (uchar) ~null_bit) |
                  (null_ptr[l_offset] & null_bit));
  }


  void evaluate_insert_default_function();


  void evaluate_update_default_function();
  virtual bool binary() const { return 1; }
  virtual bool zero_pack() const { return 1; }
  virtual enum ha_base_keytype key_type() const { return HA_KEYTYPE_BINARY; }
  virtual uint32 key_length() const { return pack_length(); }
  virtual enum_field_types type() const =0;
  virtual enum_field_types real_type() const { return type(); }
  virtual enum_field_types binlog_type() const
  {
    /*
      Binlog stores field->type() as type code by default.
      This puts MYSQL_TYPE_STRING in case of CHAR, VARCHAR, SET and ENUM,
      with extra data type details put into metadata.

      We cannot store field->type() in case of temporal types with
      fractional seconds: TIME(n), DATETIME(n) and TIMESTAMP(n),
      because binlog records with MYSQL_TYPE_TIME, MYSQL_TYPE_DATETIME
      type codes do not have metadata.
      So for temporal data types with fractional seconds we'll store
      real_type() type codes instead, i.e.
      MYSQL_TYPE_TIME2, MYSQL_TYPE_DATETIME2, MYSQL_TYPE_TIMESTAMP2,
      and put precision into metatada.

      Note: perhaps binlog should eventually be modified to store
      real_type() instead of type() for all column types.
    */
    return type();
  }
  inline  int cmp(const uchar *str) { return cmp(ptr,str); }
  virtual int cmp_max(const uchar *a, const uchar *b, uint max_len)
    { return cmp(a, b); }
  virtual int cmp(const uchar *,const uchar *)=0;
  virtual int cmp_binary(const uchar *a,const uchar *b, uint32 max_length=~0L)
  { return memcmp(a,b,pack_length()); }
  virtual int cmp_offset(uint row_offset)
  { return cmp(ptr,ptr+row_offset); }
  virtual int cmp_binary_offset(uint row_offset)
  { return cmp_binary(ptr, ptr+row_offset); };
  virtual int key_cmp(const uchar *a,const uchar *b)
  { return cmp(a, b); }
  virtual int key_cmp(const uchar *str, uint length)
  { return cmp(ptr,str); }
  virtual uint decimals() const { return 0; }
  /*
    Caller beware: sql_type can change str.Ptr, so check
    ptr() to see if it changed if you are using your own buffer
    in str and restore it with set() if needed
  */
  virtual void sql_type(String &str) const =0;

  bool is_temporal() const
  { return is_temporal_type(type()); }

  bool is_temporal_with_date() const
  { return is_temporal_type_with_date(type()); }

  bool is_temporal_with_time() const
  { return is_temporal_type_with_time(type()); }

  bool is_temporal_with_date_and_time() const
  { return is_temporal_type_with_date_and_time(type()); }

  bool is_null(my_ptrdiff_t row_offset= 0) const
  {
    /*
      if the field is NULLable, it returns NULLity based
      on null_ptr[row_offset] value. Otherwise it returns
      NULL flag depending on TABLE::null_row value.

      The table may have been marked as containing only NULL values
      for all fields if it is a NULL-complemented row of an OUTER JOIN
      or if the query is an implicitly grouped query (has aggregate
      functions but no GROUP BY clause) with no qualifying rows. If
      this is the case (in which TABLE::null_row is true) and the
      field is not nullable, the field is considered to be NULL.

      Do not change the order of testing. Fields may be associated
      with a TABLE object without being part of the current row.
      For NULL value check to work for these fields, they must
      have a valid null_ptr, and this pointer must be checked before
      TABLE::null_row. 

    */
    return real_maybe_null() ?
      test(null_ptr[row_offset] & null_bit) : table->null_row;
  }

  bool is_real_null(my_ptrdiff_t row_offset= 0) const
  { return real_maybe_null() ? test(null_ptr[row_offset] & null_bit) : false; }

  bool is_null_in_record(const uchar *record) const
  { return real_maybe_null() ? test(record[null_offset()] & null_bit) : false; }

  void set_null(my_ptrdiff_t row_offset= 0)
  {
    if (real_maybe_null())
      null_ptr[row_offset]|= null_bit;
  }

  void set_notnull(my_ptrdiff_t row_offset= 0)
  {
    if (real_maybe_null())
      null_ptr[row_offset]&= (uchar) ~null_bit;
  }

  bool maybe_null(void) const
  { return real_maybe_null() || table->maybe_null; }

  bool real_maybe_null(void) const
  { return null_ptr != 0; }

  uint null_offset(const uchar *record) const
  { return (uint) (null_ptr - record); }

  uint null_offset() const
  { return null_offset(table->record[0]); }

  void set_null_ptr(uchar *p_null_ptr, uint p_null_bit)
  {
    null_ptr= p_null_ptr;
    null_bit= p_null_bit;
  }

  enum {
    LAST_NULL_BYTE_UNDEF= 0
  };

  /*
    Find the position of the last null byte for the field.

    SYNOPSIS
      last_null_byte()

    DESCRIPTION
      Return a pointer to the last byte of the null bytes where the
      field conceptually is placed.

    RETURN VALUE
      The position of the last null byte relative to the beginning of
      the record. If the field does not use any bits of the null
      bytes, the value 0 (LAST_NULL_BYTE_UNDEF) is returned.
   */
  size_t last_null_byte() const {
    size_t bytes= do_last_null_byte();
    DBUG_PRINT("debug", ("last_null_byte() ==> %ld", (long) bytes));
    DBUG_ASSERT(bytes <= table->s->null_bytes);
    return bytes;
  }

  virtual void make_field(Send_field *);

  virtual void make_sort_key(uchar *buff, uint length) = 0;
  virtual bool optimize_range(uint idx, uint part);
  /*
    This should be true for fields which, when compared with constant
    items, can be casted to longlong. In this case we will at 'fix_fields'
    stage cast the constant items to longlongs and at the execution stage
    use field->val_int() for comparison.  Used to optimize clauses like
    'a_column BETWEEN date_const, date_const'.
  */
  virtual bool can_be_compared_as_longlong() const { return false; }
  virtual void free() {}
  virtual Field *new_field(MEM_ROOT *root, TABLE *new_table,
                           bool keep_type);
  virtual Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
                               uchar *new_ptr, uchar *new_null_ptr,
                               uint new_null_bit);

  Field *new_key_field(MEM_ROOT *root, TABLE *new_table, uchar *new_ptr)
  { return new_key_field(root, new_table, new_ptr, null_ptr, null_bit); }

  virtual Field *clone() const =0;

  virtual Field *clone(MEM_ROOT *mem_root) const =0;
  inline void move_field(uchar *ptr_arg,uchar *null_ptr_arg,uchar null_bit_arg)
  {
    ptr=ptr_arg; null_ptr=null_ptr_arg; null_bit=null_bit_arg;
  }
  inline void move_field(uchar *ptr_arg) { ptr=ptr_arg; }
  virtual void move_field_offset(my_ptrdiff_t ptr_diff)
  {
    ptr=ADD_TO_PTR(ptr,ptr_diff, uchar*);
    if (null_ptr)
      null_ptr=ADD_TO_PTR(null_ptr,ptr_diff,uchar*);
  }
  virtual void get_image(uchar *buff, uint length, const CHARSET_INFO *cs)
    { memcpy(buff,ptr,length); }
  virtual void set_image(const uchar *buff,uint length,
                         const CHARSET_INFO *cs)
    { memcpy(ptr,buff,length); }


  /*
    Copy a field part into an output buffer.

    SYNOPSIS
      Field::get_key_image()
      buff   [out] output buffer
      length       output buffer size
      type         itMBR for geometry blobs, otherwise itRAW

    DESCRIPTION
      This function makes a copy of field part of size equal to or
      less than "length" parameter value.
      For fields of string types (CHAR, VARCHAR, TEXT) the rest of buffer
      is padded by zero byte.

    NOTES
      For variable length character fields (i.e. UTF-8) the "length"
      parameter means a number of output buffer bytes as if all field
      characters have maximal possible size (mbmaxlen). In the other words,
      "length" parameter is a number of characters multiplied by
      field_charset->mbmaxlen.

    RETURN
      Number of copied bytes (excluding padded zero bytes -- see above).
  */

  virtual uint get_key_image(uchar *buff, uint length, imagetype type)
  {
    get_image(buff, length, &my_charset_bin);
    return length;
  }
  virtual void set_key_image(const uchar *buff,uint length)
    { set_image(buff,length, &my_charset_bin); }
  inline longlong val_int_offset(uint row_offset)
    {
      ptr+=row_offset;
      longlong tmp=val_int();
      ptr-=row_offset;
      return tmp;
    }
  inline longlong val_int(const uchar *new_ptr)
  {
    uchar *old_ptr= ptr;
    longlong return_value;
    ptr= (uchar*) new_ptr;
    return_value= val_int();
    ptr= old_ptr;
    return return_value;
  }
  inline String *val_str(String *str, const uchar *new_ptr)
  {
    uchar *old_ptr= ptr;
    ptr= (uchar*) new_ptr;
    val_str(str);
    ptr= old_ptr;
    return str;
  }
  virtual bool send_binary(Protocol *protocol);

  virtual uchar *pack(uchar *to, const uchar *from,
                      uint max_length, bool low_byte_first);
  uchar *pack(uchar *to, const uchar *from)
  {
    DBUG_ENTER("Field::pack");
    uchar *result= this->pack(to, from, UINT_MAX, table->s->db_low_byte_first);
    DBUG_RETURN(result);
  }

  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first);
  const uchar *unpack(uchar* to, const uchar *from)
  {
    DBUG_ENTER("Field::unpack");
    const uchar *result= unpack(to, from, 0U, table->s->db_low_byte_first);
    DBUG_RETURN(result);
  }

  virtual uint packed_col_length(const uchar *to, uint length)
  { return length;}
  virtual uint max_packed_col_length(uint max_length)
  { return max_length;}

  uint offset(uchar *record)
  {
    return (uint) (ptr - record);
  }
  void copy_from_tmp(int offset);
  uint fill_cache_field(struct st_cache_field *copy);
  virtual bool get_date(MYSQL_TIME *ltime,uint fuzzydate);
  virtual bool get_time(MYSQL_TIME *ltime);
  virtual const CHARSET_INFO *charset(void) const { return &my_charset_bin; }
  virtual const CHARSET_INFO *charset_for_protocol(void) const
  { return binary() ? &my_charset_bin : charset(); }
  virtual const CHARSET_INFO *sort_charset(void) const { return charset(); }
  virtual bool has_charset(void) const { return FALSE; }
  /*
    match_collation_to_optimize_range() is to distinguish in
    range optimizer (see opt_range.cc) between real string types:
      CHAR, VARCHAR, TEXT
    and the other string-alike types with result_type() == STRING_RESULT:
      DATE, TIME, DATETIME, TIMESTAMP
    We need it to decide whether to test if collation of the operation
    matches collation of the field (needed only for real string types).
    QQ: shouldn't DATE/TIME types have their own XXX_RESULT types eventually?
  */
  virtual bool match_collation_to_optimize_range() const { return false; };
  virtual enum Derivation derivation(void) const
  { return DERIVATION_IMPLICIT; }
  virtual uint repertoire(void) const { return MY_REPERTOIRE_UNICODE30; }
  virtual void set_derivation(enum Derivation derivation_arg) { }
  bool set_warning(Sql_condition::enum_warning_level, unsigned int code,
                   int cuted_increment) const;
  inline bool check_overflow(int op_result)
  {
    return (op_result == E_DEC_OVERFLOW);
  }
  inline bool check_truncated(int op_result)
  {
    return (op_result == E_DEC_TRUNCATED);
  }
  bool warn_if_overflow(int op_result);
  void init(TABLE *table_arg)
  {
    orig_table= table= table_arg;
    table_name= &table_arg->alias;
  }

  /* maximum possible display length */
  virtual uint32 max_display_length()= 0;

  virtual uint is_equal(Create_field *new_field);
  /* convert decimal to longlong with overflow check */
  longlong convert_decimal2longlong(const my_decimal *val, bool unsigned_flag,
                                    bool *has_overflow);
  /* The max. number of characters */
  virtual uint32 char_length()
  {
    return field_length / charset()->mbmaxlen;
  }

  virtual geometry_type get_geometry_type()
  {
    /* shouldn't get here. */
    DBUG_ASSERT(0);
    return GEOM_GEOMETRY;
  }
#ifndef DBUG_OFF
  /* Print field value into debug trace, in NULL-aware way. */
  void dbug_print()
  {
    if (is_real_null())
      fprintf(DBUG_FILE, "NULL");
    else
    {
      char buf[256];
      String str(buf, sizeof(buf), &my_charset_bin);
      str.length(0);
      String *pstr;
      pstr= val_str(&str);
      fprintf(DBUG_FILE, "'%s'", pstr->c_ptr_safe());
    }
  }
#endif

  ha_storage_media field_storage_type() const
  {
    return (ha_storage_media)
      ((flags >> FIELD_FLAGS_STORAGE_MEDIA) & 3);
  }

  void set_storage_type(ha_storage_media storage_type_arg)
  {
    DBUG_ASSERT(field_storage_type() == HA_SM_DEFAULT);
    flags |= (storage_type_arg << FIELD_FLAGS_STORAGE_MEDIA);
  }

  column_format_type column_format() const
  {
    return (column_format_type)
      ((flags >> FIELD_FLAGS_COLUMN_FORMAT) & 3);
  }

  void set_column_format(column_format_type column_format_arg)
  {
    DBUG_ASSERT(column_format() == COLUMN_FORMAT_TYPE_DEFAULT);
    flags |= (column_format_arg << FIELD_FLAGS_COLUMN_FORMAT);
  }

  /* Validate the value stored in a field */
  virtual type_conversion_status validate_stored_val(THD *thd)
  { return TYPE_OK; }

  /* Hash value */
  virtual void hash(ulong *nr, ulong *nr2);
  friend int cre_myisam(char * name, register TABLE *form, uint options,
                        ulonglong auto_increment_value);
  friend class Copy_field;
  friend class Item_avg_field;
  friend class Item_std_field;
  friend class Item_sum_num;
  friend class Item_sum_sum;
  friend class Item_sum_str;
  friend class Item_sum_count;
  friend class Item_sum_avg;
  friend class Item_sum_std;
  friend class Item_sum_min;
  friend class Item_sum_max;
  friend class Item_func_group_concat;

private:
  /*
    Primitive for implementing last_null_byte().

    SYNOPSIS
      do_last_null_byte()

    DESCRIPTION
      Primitive for the implementation of the last_null_byte()
      function. This represents the inheritance interface and can be
      overridden by subclasses.
   */
  virtual size_t do_last_null_byte() const;

  virtual int do_save_field_metadata(uchar *metadata_ptr)
  { return 0; }

protected:
  static void handle_int16(uchar *to, const uchar *from,
                           bool low_byte_first_from, bool low_byte_first_to)
  {
    int16 val;
#ifdef WORDS_BIGENDIAN
    if (low_byte_first_from)
      val = sint2korr(from);
    else
#endif
      shortget(val, from);

#ifdef WORDS_BIGENDIAN
    if (low_byte_first_to)
      int2store(to, val);
    else
#endif
      shortstore(to, val);
  }

  static void handle_int24(uchar *to, const uchar *from,
                           bool low_byte_first_from, bool low_byte_first_to)
  {
    int32 val;
#ifdef WORDS_BIGENDIAN
    if (low_byte_first_from)
      val = sint3korr(from);
    else
#endif
      val= (from[0] << 16) + (from[1] << 8) + from[2];

#ifdef WORDS_BIGENDIAN
    if (low_byte_first_to)
      int2store(to, val);
    else
#endif
    {
      to[0]= 0xFF & (val >> 16);
      to[1]= 0xFF & (val >> 8);
      to[2]= 0xFF & val;
    }
  }

  /*
    Helper function to pack()/unpack() int32 values
  */
  static void handle_int32(uchar *to, const uchar *from,
                           bool low_byte_first_from, bool low_byte_first_to)
  {
    int32 val;
#ifdef WORDS_BIGENDIAN
    if (low_byte_first_from)
      val = sint4korr(from);
    else
#endif
      longget(val, from);

#ifdef WORDS_BIGENDIAN
    if (low_byte_first_to)
      int4store(to, val);
    else
#endif
      longstore(to, val);
  }

  /*
    Helper function to pack()/unpack() int64 values
  */
  static void handle_int64(uchar* to, const uchar *from,
                           bool low_byte_first_from, bool low_byte_first_to)
  {
    int64 val;
#ifdef WORDS_BIGENDIAN
    if (low_byte_first_from)
      val = sint8korr(from);
    else
#endif
      longlongget(val, from);

#ifdef WORDS_BIGENDIAN
    if (low_byte_first_to)
      int8store(to, val);
    else
#endif
      longlongstore(to, val);
  }

  uchar *pack_int16(uchar *to, const uchar *from, bool low_byte_first_to)
  {
    handle_int16(to, from, table->s->db_low_byte_first, low_byte_first_to);
    return to  + sizeof(int16);
  }

  const uchar *unpack_int16(uchar* to, const uchar *from,
                            bool low_byte_first_from)
  {
    handle_int16(to, from, low_byte_first_from, table->s->db_low_byte_first);
    return from + sizeof(int16);
  }

  uchar *pack_int24(uchar *to, const uchar *from, bool low_byte_first_to)
  {
    handle_int24(to, from, table->s->db_low_byte_first, low_byte_first_to);
    return to + 3;
  }

  const uchar *unpack_int24(uchar* to, const uchar *from,
                            bool low_byte_first_from)
  {
    handle_int24(to, from, low_byte_first_from, table->s->db_low_byte_first);
    return from + 3;
  }

  uchar *pack_int32(uchar *to, const uchar *from, bool low_byte_first_to)
  {
    handle_int32(to, from, table->s->db_low_byte_first, low_byte_first_to);
    return to  + sizeof(int32);
  }

  const uchar *unpack_int32(uchar* to, const uchar *from,
                            bool low_byte_first_from)
  {
    handle_int32(to, from, low_byte_first_from, table->s->db_low_byte_first);
    return from + sizeof(int32);
  }

  uchar *pack_int64(uchar* to, const uchar *from, bool low_byte_first_to)
  {
    handle_int64(to, from, table->s->db_low_byte_first, low_byte_first_to);
    return to + sizeof(int64);
  }

  const uchar *unpack_int64(uchar* to, const uchar *from,
                            bool low_byte_first_from)
  {
    handle_int64(to, from, low_byte_first_from, table->s->db_low_byte_first);
    return from + sizeof(int64);
  }

  bool field_flags_are_binary()
  {
    return (flags & (BINCMP_FLAG | BINARY_FLAG)) != 0;
  }

};


class Field_num :public Field {
public:
  const uint8 dec;
  bool zerofill,unsigned_flag;  // Purify cannot handle bit fields
  Field_num(uchar *ptr_arg,uint32 len_arg, uchar *null_ptr_arg,
            uchar null_bit_arg, utype unireg_check_arg,
            const char *field_name_arg,
            uint8 dec_arg, bool zero_arg, bool unsigned_arg);
  Item_result result_type () const { return REAL_RESULT; }
  enum Derivation derivation(void) const { return DERIVATION_NUMERIC; }
  uint repertoire(void) const { return MY_REPERTOIRE_NUMERIC; }
  const CHARSET_INFO *charset(void) const { return &my_charset_numeric; }
  void prepend_zeros(String *value);
  void add_zerofill_and_unsigned(String &res) const;
  friend class Create_field;
  uint decimals() const { return (uint) dec; }
  bool eq_def(Field *field);
  type_conversion_status store_decimal(const my_decimal *);
  type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  my_decimal *val_decimal(my_decimal *);
  bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
  bool get_time(MYSQL_TIME *ltime);
  uint is_equal(Create_field *new_field);
  uint row_pack_length() const { return pack_length(); }
  uint32 pack_length_from_metadata(uint field_metadata) {
    uint32 length= pack_length();
    DBUG_PRINT("result", ("pack_length_from_metadata(%d): %u",
                          field_metadata, length));
    return length;
  }
  type_conversion_status check_int(const CHARSET_INFO *cs,
                                   const char *str, int length,
                                   const char *int_end, int error);
  type_conversion_status get_int(const CHARSET_INFO *cs,
                                 const char *from, uint len,
                                 longlong *rnd, ulonglong unsigned_max,
                                 longlong signed_min, longlong signed_max);
};


class Field_str :public Field {
protected:
  const CHARSET_INFO *field_charset;
  enum Derivation field_derivation;
public:
  Field_str(uchar *ptr_arg,uint32 len_arg, uchar *null_ptr_arg,
            uchar null_bit_arg, utype unireg_check_arg,
            const char *field_name_arg, const CHARSET_INFO *charset);
  Item_result result_type () const { return STRING_RESULT; }
  Item_result numeric_context_result_type() const
  { 
    return REAL_RESULT; 
  }
  uint decimals() const { return NOT_FIXED_DEC; }
  void make_field(Send_field *field);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val)=0;
  type_conversion_status store_decimal(const my_decimal *);
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *cs)=0;
  uint repertoire(void) const
  {
    return my_charset_repertoire(field_charset);
  }
  const CHARSET_INFO *charset(void) const { return field_charset; }
  void set_charset(const CHARSET_INFO *charset_arg)
  { field_charset= charset_arg; }
  enum Derivation derivation(void) const { return field_derivation; }
  virtual void set_derivation(enum Derivation derivation_arg)
  { field_derivation= derivation_arg; }
  bool binary() const { return field_charset == &my_charset_bin; }
  uint32 max_display_length() { return field_length; }
  friend class Create_field;
  virtual bool str_needs_quotes() { return TRUE; }
  uint is_equal(Create_field *new_field);
};


/* base class for Field_string, Field_varstring and Field_blob */

class Field_longstr :public Field_str
{
protected:
  type_conversion_status report_if_important_data(const char *ptr,
                                                  const char *end,
                                                  bool count_spaces) const;
  type_conversion_status
    check_string_copy_error(const char *well_formed_error_pos,
                            const char *cannot_convert_error_pos,
                            const char *from_end_pos,
                            const char *end,
                            bool count_spaces,
                            const CHARSET_INFO *cs) const;
public:
  Field_longstr(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
                uchar null_bit_arg, utype unireg_check_arg,
                const char *field_name_arg, const CHARSET_INFO *charset_arg)
    :Field_str(ptr_arg, len_arg, null_ptr_arg, null_bit_arg, unireg_check_arg,
               field_name_arg, charset_arg)
    {}

  type_conversion_status store_decimal(const my_decimal *d);
  uint32 max_data_length() const;
};

/* base class for float and double and decimal (old one) */
class Field_real :public Field_num {
public:
  my_bool not_fixed;

  Field_real(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
             uchar null_bit_arg, utype unireg_check_arg,
             const char *field_name_arg,
             uint8 dec_arg, bool zero_arg, bool unsigned_arg)
    :Field_num(ptr_arg, len_arg, null_ptr_arg, null_bit_arg, unireg_check_arg,
               field_name_arg, dec_arg, zero_arg, unsigned_arg),
    not_fixed(dec_arg >= NOT_FIXED_DEC)
    {}
  type_conversion_status store_decimal(const my_decimal *);
  type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  my_decimal *val_decimal(my_decimal *);
  bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
  bool get_time(MYSQL_TIME *ltime);
  bool truncate(double *nr, double max_length);
  uint32 max_display_length() { return field_length; }
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first);
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length, bool low_byte_first);
};


class Field_decimal :public Field_real {
public:
  Field_decimal(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
                uchar null_bit_arg,
                enum utype unireg_check_arg, const char *field_name_arg,
                uint8 dec_arg,bool zero_arg,bool unsigned_arg)
    :Field_real(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                unireg_check_arg, field_name_arg,
                dec_arg, zero_arg, unsigned_arg)
    {}
  enum_field_types type() const { return MYSQL_TYPE_DECIMAL;}
  enum ha_base_keytype key_type() const
  { return zerofill ? HA_KEYTYPE_BINARY : HA_KEYTYPE_NUM; }
  type_conversion_status reset(void);
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  void overflow(bool negative);
  bool zero_pack() const { return 0; }
  void sql_type(String &str) const;
  Field_decimal *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_DECIMAL);
    return new (mem_root) Field_decimal(*this);
  }
  Field_decimal *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_DECIMAL);
    return new Field_decimal(*this);
  }
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first)
  {
    return Field::unpack(to, from, param_data, low_byte_first);
  }
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length, bool low_byte_first)
  {
    return Field::pack(to, from, max_length, low_byte_first);
  }
};


/* New decimal/numeric field which use fixed point arithmetic */
class Field_new_decimal :public Field_num {
private:
  int do_save_field_metadata(uchar *first_byte);
public:

  /* The maximum number of decimal digits can be stored */
  uint precision;
  uint bin_size;
  /*
    Constructors take max_length of the field as a parameter - not the
    precision as the number of decimal digits allowed.
    So for example we need to count length from precision handling
    CREATE TABLE ( DECIMAL(x,y)) 
  */
  Field_new_decimal(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
                    uchar null_bit_arg,
                    enum utype unireg_check_arg, const char *field_name_arg,
                    uint8 dec_arg, bool zero_arg, bool unsigned_arg);
  Field_new_decimal(uint32 len_arg, bool maybe_null_arg,
                    const char *field_name_arg, uint8 dec_arg,
                    bool unsigned_arg);
  enum_field_types type() const { return MYSQL_TYPE_NEWDECIMAL;}
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_BINARY; }
  Item_result result_type () const { return DECIMAL_RESULT; }
  type_conversion_status reset(void);
  type_conversion_status store_value(const my_decimal *decimal_value);
  void set_value_on_overflow(my_decimal *decimal_value, bool sign);
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  type_conversion_status store_decimal(const my_decimal *);
  double val_real(void);
  longlong val_int(void);
  my_decimal *val_decimal(my_decimal *);
  bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
  bool get_time(MYSQL_TIME *ltime);
  String *val_str(String*, String *);
  int cmp(const uchar *, const uchar *);
  void make_sort_key(uchar *buff, uint length);
  bool zero_pack() const { return 0; }
  void sql_type(String &str) const;
  uint32 max_display_length() { return field_length; }
  uint32 pack_length() const { return (uint32) bin_size; }
  uint pack_length_from_metadata(uint field_metadata);
  uint row_pack_length() const { return pack_length(); }
  bool compatible_field_size(uint field_metadata, Relay_log_info *rli,
                             uint16 mflags, int *order_var);
  uint is_equal(Create_field *new_field);
  Field_new_decimal *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_NEWDECIMAL);
    return new (mem_root) Field_new_decimal(*this);
  }
  Field_new_decimal *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_NEWDECIMAL);
    return new Field_new_decimal(*this);
  }
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first);
  static Field *create_from_item (Item *);
};


class Field_tiny :public Field_num {
public:
  Field_tiny(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
             uchar null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg,
             bool zero_arg, bool unsigned_arg)
    :Field_num(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
               unireg_check_arg, field_name_arg,
               0, zero_arg,unsigned_arg)
    {}
  enum Item_result result_type () const { return INT_RESULT; }
  enum_field_types type() const { return MYSQL_TYPE_TINY;}
  enum ha_base_keytype key_type() const
    { return unsigned_flag ? HA_KEYTYPE_BINARY : HA_KEYTYPE_INT8; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void) { ptr[0]=0; return TYPE_OK; }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return 1; }
  void sql_type(String &str) const;
  uint32 max_display_length() { return 4; }
  Field_tiny *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_TINY);
    return new (mem_root) Field_tiny(*this);
  }
  Field_tiny *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_TINY);
    return new Field_tiny(*this);
  }
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length, bool low_byte_first)
  {
    *to= *from;
    return to + 1;
  }

  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first)
  {
    *to= *from;
    return from + 1;
  }
};


class Field_short :public Field_num {
public:
  Field_short(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
              uchar null_bit_arg,
              enum utype unireg_check_arg, const char *field_name_arg,
              bool zero_arg, bool unsigned_arg)
    :Field_num(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
               unireg_check_arg, field_name_arg,
               0, zero_arg,unsigned_arg)
    {}
  Field_short(uint32 len_arg,bool maybe_null_arg, const char *field_name_arg,
              bool unsigned_arg)
    :Field_num((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "": 0,0,
               NONE, field_name_arg, 0, 0, unsigned_arg)
    {}
  enum Item_result result_type () const { return INT_RESULT; }
  enum_field_types type() const { return MYSQL_TYPE_SHORT;}
  enum ha_base_keytype key_type() const
    { return unsigned_flag ? HA_KEYTYPE_USHORT_INT : HA_KEYTYPE_SHORT_INT;}
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void) { ptr[0]=ptr[1]=0; return TYPE_OK; }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return 2; }
  void sql_type(String &str) const;
  uint32 max_display_length() { return 6; }
  Field_short *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_SHORT);
    return new (mem_root) Field_short(*this);
  }
  Field_short *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_SHORT);
    return new Field_short(*this);
  }
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length, bool low_byte_first)
  {
    return pack_int16(to, from, low_byte_first);
  }

  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first)
  {
    return unpack_int16(to, from, low_byte_first);
  }
};

class Field_medium :public Field_num {
public:
  Field_medium(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
              uchar null_bit_arg,
              enum utype unireg_check_arg, const char *field_name_arg,
              bool zero_arg, bool unsigned_arg)
    :Field_num(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
               unireg_check_arg, field_name_arg,
               0, zero_arg,unsigned_arg)
    {}
  enum Item_result result_type () const { return INT_RESULT; }
  enum_field_types type() const { return MYSQL_TYPE_INT24;}
  enum ha_base_keytype key_type() const
    { return unsigned_flag ? HA_KEYTYPE_UINT24 : HA_KEYTYPE_INT24; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=0;
    return TYPE_OK;
  }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return 3; }
  void sql_type(String &str) const;
  uint32 max_display_length() { return 8; }
  Field_medium *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_INT24);
    return new (mem_root) Field_medium(*this);
  }
  Field_medium *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_INT24);
    return new Field_medium(*this);
  }
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length, bool low_byte_first)
  {
    return Field::pack(to, from, max_length, low_byte_first);
  }

  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first)
  {
    return Field::unpack(to, from, param_data, low_byte_first);
  }
};


class Field_long :public Field_num {
public:

  static const int PACK_LENGTH= 4;

  Field_long(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
             uchar null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg,
             bool zero_arg, bool unsigned_arg)
    :Field_num(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
               unireg_check_arg, field_name_arg,
               0, zero_arg,unsigned_arg)
    {}
  Field_long(uint32 len_arg,bool maybe_null_arg, const char *field_name_arg,
             bool unsigned_arg)
    :Field_num((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "": 0,0,
               NONE, field_name_arg,0,0,unsigned_arg)
    {}
  enum Item_result result_type () const { return INT_RESULT; }
  enum_field_types type() const { return MYSQL_TYPE_LONG;}
  enum ha_base_keytype key_type() const
    { return unsigned_flag ? HA_KEYTYPE_ULONG_INT : HA_KEYTYPE_LONG_INT; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=ptr[3]=0;
    return TYPE_OK;
  }
  double val_real(void);
  longlong val_int(void);
  bool send_binary(Protocol *protocol);
  String *val_str(String*,String *);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return PACK_LENGTH; }
  void sql_type(String &str) const;
  uint32 max_display_length() { return MY_INT32_NUM_DECIMAL_DIGITS; }
  Field_long *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_LONG);
    return new (mem_root) Field_long(*this);
  }
  Field_long *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_LONG);
    return new Field_long(*this);
  }
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length __attribute__((unused)),
                      bool low_byte_first)
  {
    return pack_int32(to, from, low_byte_first);
  }
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data __attribute__((unused)),
                              bool low_byte_first)
  {
    return unpack_int32(to, from, low_byte_first);
  }
};


#ifdef HAVE_LONG_LONG
class Field_longlong :public Field_num {
public:
  static const int PACK_LENGTH= 8;

  Field_longlong(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
              uchar null_bit_arg,
              enum utype unireg_check_arg, const char *field_name_arg,
              bool zero_arg, bool unsigned_arg)
    :Field_num(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
               unireg_check_arg, field_name_arg,
               0, zero_arg,unsigned_arg)
    {}
  Field_longlong(uint32 len_arg,bool maybe_null_arg,
                 const char *field_name_arg,
                  bool unsigned_arg)
    :Field_num((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "": 0,0,
               NONE, field_name_arg,0,0,unsigned_arg)
    {}
  enum Item_result result_type () const { return INT_RESULT; }
  enum_field_types type() const { return MYSQL_TYPE_LONGLONG;}
  enum ha_base_keytype key_type() const
    { return unsigned_flag ? HA_KEYTYPE_ULONGLONG : HA_KEYTYPE_LONGLONG; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=ptr[3]=ptr[4]=ptr[5]=ptr[6]=ptr[7]=0;
    return TYPE_OK;
  }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return PACK_LENGTH; }
  void sql_type(String &str) const;
  bool can_be_compared_as_longlong() const { return true; }
  uint32 max_display_length() { return 20; }
  Field_longlong *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_LONGLONG);
    return new (mem_root) Field_longlong(*this);
  }
  Field_longlong *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_LONGLONG);
    return new Field_longlong(*this);
  }
  virtual uchar *pack(uchar* to, const uchar *from,
                      uint max_length  __attribute__((unused)),
                      bool low_byte_first)
  {
    return pack_int64(to, from, low_byte_first);
  }
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data __attribute__((unused)),
                              bool low_byte_first)
  {
    return unpack_int64(to, from, low_byte_first);
  }
};
#endif


class Field_float :public Field_real {
public:
  Field_float(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
              uchar null_bit_arg,
              enum utype unireg_check_arg, const char *field_name_arg,
              uint8 dec_arg,bool zero_arg,bool unsigned_arg)
    :Field_real(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                unireg_check_arg, field_name_arg,
                dec_arg, zero_arg, unsigned_arg)
    {}
  Field_float(uint32 len_arg, bool maybe_null_arg, const char *field_name_arg,
              uint8 dec_arg)
    :Field_real((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "": 0, (uint) 0,
                NONE, field_name_arg, dec_arg, 0, 0)
    {}
  enum_field_types type() const { return MYSQL_TYPE_FLOAT;}
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_FLOAT; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void)
  {
    memset(ptr, 0, sizeof(float));
    return TYPE_OK;
  }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return sizeof(float); }
  uint row_pack_length() const { return pack_length(); }
  void sql_type(String &str) const;
  Field_float *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_FLOAT);
    return new (mem_root) Field_float(*this);
  }
  Field_float *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_FLOAT);
    return new Field_float(*this);
  }
private:
  int do_save_field_metadata(uchar *first_byte);
};


class Field_double :public Field_real {
public:
  Field_double(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
               uchar null_bit_arg,
               enum utype unireg_check_arg, const char *field_name_arg,
               uint8 dec_arg,bool zero_arg,bool unsigned_arg)
    :Field_real(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                unireg_check_arg, field_name_arg,
                dec_arg, zero_arg, unsigned_arg)
    {}
  Field_double(uint32 len_arg, bool maybe_null_arg, const char *field_name_arg,
               uint8 dec_arg)
    :Field_real((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "" : 0, (uint) 0,
                NONE, field_name_arg, dec_arg, 0, 0)
    {}
  Field_double(uint32 len_arg, bool maybe_null_arg, const char *field_name_arg,
               uint8 dec_arg, my_bool not_fixed_arg)
    :Field_real((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "" : 0, (uint) 0,
                NONE, field_name_arg, dec_arg, 0, 0)
    {not_fixed= not_fixed_arg; }
  enum_field_types type() const { return MYSQL_TYPE_DOUBLE;}
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_DOUBLE; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status reset(void)
  {
    memset(ptr, 0, sizeof(double));
    return TYPE_OK;
  }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return sizeof(double); }
  uint row_pack_length() const { return pack_length(); }
  void sql_type(String &str) const;
  Field_double *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_DOUBLE);
    return new (mem_root) Field_double(*this);
  }
  Field_double *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_DOUBLE);
    return new Field_double(*this);
  }
private:
  int do_save_field_metadata(uchar *first_byte);
};


/* Everything saved in this will disappear. It will always return NULL */

class Field_null :public Field_str {
  static uchar null[1];
public:
  Field_null(uchar *ptr_arg, uint32 len_arg,
             enum utype unireg_check_arg, const char *field_name_arg,
             const CHARSET_INFO *cs)
    :Field_str(ptr_arg, len_arg, null, 1,
               unireg_check_arg, field_name_arg, cs)
    {}
  enum_field_types type() const { return MYSQL_TYPE_NULL;}
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *cs)
  {
    null[0]= 1;
    return TYPE_OK;
  }
  type_conversion_status store(double nr)   { null[0]=1; return TYPE_OK; }
  type_conversion_status store(longlong nr, bool unsigned_val)
  {
    null[0]=1;
    return TYPE_OK;
  }
  type_conversion_status store_decimal(const my_decimal *d)
  {
    null[0]=1;
    return TYPE_OK;
  }
  type_conversion_status reset(void)       { return TYPE_OK; }
  double val_real(void)         { return 0.0;}
  longlong val_int(void)        { return 0;}
  my_decimal *val_decimal(my_decimal *) { return 0; }
  String *val_str(String *value,String *value2)
  { value2->length(0); return value2;}
  int cmp(const uchar *a, const uchar *b) { return 0;}
  void make_sort_key(uchar *buff, uint length)  {}
  uint32 pack_length() const { return 0; }
  void sql_type(String &str) const;
  uint32 max_display_length() { return 4; }
  Field_null *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_NULL);
    return new (mem_root) Field_null(*this);
  }
  Field_null *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_NULL);
    return new Field_null(*this);
  }
};


/*
  Abstract class for TIME, DATE, DATETIME, TIMESTAMP
  with and without fractional part.
*/
class Field_temporal :public Field {
protected:
  uint8 dec; // Number of fractional digits

  uint8 normalize_dec(uint8 dec_arg)
  { return dec_arg == NOT_FIXED_DEC ? DATETIME_MAX_DECIMALS : dec_arg; }

  virtual type_conversion_status store_internal(const MYSQL_TIME *ltime,
                                                int *error)= 0;

  virtual type_conversion_status store_internal_with_round(MYSQL_TIME *ltime,
                                                           int *warnings)= 0;

  type_conversion_status store_lldiv_t(const lldiv_t *lld, int *warning);

  virtual bool convert_str_to_TIME(const char *str, uint len,
                                   const CHARSET_INFO *cs,
                                   MYSQL_TIME *ltime, 
                                   MYSQL_TIME_STATUS *status)= 0;
  virtual type_conversion_status convert_number_to_TIME(longlong nr,
                                                        bool unsigned_val,
                                                        int nanoseconds,
                                                        MYSQL_TIME *ltime,
                                                        int *warning)= 0;

  longlong convert_number_to_datetime(longlong nr, bool unsigned_val,
                                      MYSQL_TIME *ltime, int *warning);

  void set_warnings(ErrConvString str, int warnings);

  virtual ulonglong date_flags(const THD *thd)
  {
    return 0;
  }
  inline ulonglong date_flags()
  {
    return date_flags(table ? table->in_use : current_thd);
  }

  void set_datetime_warning(Sql_condition::enum_warning_level level, uint code,
                            ErrConvString str,
                            timestamp_type ts_type, int cuted_increment);
public:
  Field_temporal(uchar *ptr_arg,
                 uchar *null_ptr_arg, uchar null_bit_arg,
                 enum utype unireg_check_arg, const char *field_name_arg,
                 uint32 len_arg, uint8 dec_arg)
    :Field(ptr_arg,
           len_arg + ((dec= normalize_dec(dec_arg)) ? dec + 1 : 0),
           null_ptr_arg, null_bit_arg,
           unireg_check_arg, field_name_arg)
    { flags|= BINARY_FLAG; }
  Field_temporal(bool maybe_null_arg, const char *field_name_arg,
                 uint32 len_arg, uint8 dec_arg)
    :Field((uchar *) 0, 
           len_arg + ((dec= normalize_dec(dec_arg)) ? dec + 1 : 0),
           maybe_null_arg ? (uchar *) "" : 0, 0,
           NONE, field_name_arg)
    { flags|= BINARY_FLAG; }
  virtual Item_result result_type() const { return STRING_RESULT; }
  virtual uint32 max_display_length() { return field_length; }
  virtual bool str_needs_quotes() { return TRUE; }
  virtual uint is_equal(Create_field *new_field);
  Item_result numeric_context_result_type() const
  {
    return dec ? DECIMAL_RESULT : INT_RESULT;
  }
  enum Item_result cmp_type() const { return INT_RESULT; }
  enum Derivation derivation() const { return DERIVATION_NUMERIC; }
  uint repertoire() const { return MY_REPERTOIRE_NUMERIC; }
  const CHARSET_INFO *charset() const { return &my_charset_numeric; }
  bool can_be_compared_as_longlong() const { return true; }
  bool binary() const { return true; }
  type_conversion_status store(const char *str, uint len,
                               const CHARSET_INFO *cs);
  type_conversion_status store_decimal(const my_decimal *decimal);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status store(double nr);
  double val_real() // FSP-enable types redefine it.
  {
    return (double) val_int();
  }
  my_decimal *val_decimal(my_decimal *decimal_value); // FSP types redefine it
};


class Field_temporal_with_date :public Field_temporal {
protected:
  virtual bool get_date_internal(MYSQL_TIME *ltime)= 0;

  bool get_internal_check_zero(MYSQL_TIME *ltime, uint fuzzydate);
  
  type_conversion_status convert_number_to_TIME(longlong nr, bool unsigned_val,
                                                int nanoseconds,
                                                MYSQL_TIME *ltime,
                                                int *warning);
  bool convert_str_to_TIME(const char *str, uint len, const CHARSET_INFO *cs,
                           MYSQL_TIME *ltime, MYSQL_TIME_STATUS *status);
  type_conversion_status store_internal_with_round(MYSQL_TIME *ltime,
                                                   int *warnings);
public:
  Field_temporal_with_date(uchar *ptr_arg, uchar *null_ptr_arg,
                           uchar null_bit_arg,
                           enum utype unireg_check_arg,
                           const char *field_name_arg,
                           uint8 int_length_arg, uint8 dec_arg)
    :Field_temporal(ptr_arg, null_ptr_arg, null_bit_arg,
                    unireg_check_arg, field_name_arg,
                    int_length_arg, dec_arg)
    { }
  Field_temporal_with_date(bool maybe_null_arg, const char *field_name_arg,
                           uint int_length_arg, uint8 dec_arg)
    :Field_temporal((uchar*) 0, maybe_null_arg ? (uchar*) "": 0, 0,
                    NONE, field_name_arg, int_length_arg, dec_arg)
    { }
  bool send_binary(Protocol *protocol);
  type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  String *val_str(String *, String *);
  longlong val_time_temporal();
  longlong val_date_temporal();
  bool get_time(MYSQL_TIME *ltime)
  {
    return get_date(ltime, TIME_FUZZY_DATE);
  }
  /* Validate the value stored in a field */
  virtual type_conversion_status validate_stored_val(THD *thd);
};


class Field_temporal_with_date_and_time :public Field_temporal_with_date {
private:
  int do_save_field_metadata(uchar *metadata_ptr)
  {
    if (decimals())
    {
      *metadata_ptr= decimals();
      return 1;
    }
    return 0;
  }
protected:
  void init_timestamp_flags();
  virtual void store_timestamp_internal(const struct timeval *tm)= 0;
  bool convert_TIME_to_timestamp(THD *thd, const MYSQL_TIME *ltime,
                                 struct timeval *tm, int *error);

public:
  Field_temporal_with_date_and_time(uchar *ptr_arg, uchar *null_ptr_arg,
                                    uchar null_bit_arg,
                                    enum utype unireg_check_arg,
                                    const char *field_name_arg,
                                    uint8 dec_arg)
    :Field_temporal_with_date(ptr_arg, null_ptr_arg, null_bit_arg,
                              unireg_check_arg, field_name_arg,
                              MAX_DATETIME_WIDTH, dec_arg)
    { }
  void store_timestamp(const struct timeval *tm);
};


class Field_temporal_with_date_and_timef :
  public Field_temporal_with_date_and_time {
private:
  int do_save_field_metadata(uchar *metadata_ptr)
  {
    *metadata_ptr= decimals();
    return 1;
  }
public:
  Field_temporal_with_date_and_timef(uchar *ptr_arg, uchar *null_ptr_arg,
                                     uchar null_bit_arg,
                                     enum utype unireg_check_arg,
                                     const char *field_name_arg,
                                     uint8 dec_arg)
    :Field_temporal_with_date_and_time(ptr_arg, null_ptr_arg, null_bit_arg,
                                       unireg_check_arg, field_name_arg,
                                       dec_arg)
    { }
  Field_temporal_with_date_and_timef(bool maybe_null_arg,
                                     const char *field_name_arg,
                                     uint8 dec_arg)
    :Field_temporal_with_date_and_time((uchar *) 0,
                                       maybe_null_arg ? (uchar*) "" : 0, 0,
                                       NONE, field_name_arg, dec_arg)
    { }

  uint decimals() const { return dec; }
  const CHARSET_INFO *sort_charset() const { return &my_charset_bin; }
  void make_sort_key(uchar *to, uint length) { memcpy(to, ptr, length); }
  int cmp(const uchar *a_ptr, const uchar *b_ptr)
  {
    return memcmp(a_ptr, b_ptr, pack_length());
  }
  uint row_pack_length() const { return pack_length(); }
  double val_real();
  longlong val_int();
  my_decimal *val_decimal(my_decimal *decimal_value);
};


/*
  Field implementing TIMESTAMP data type without fractional seconds.
  We will be removed eventually.
*/
class Field_timestamp :public Field_temporal_with_date_and_time {
protected:
  ulonglong date_flags(const THD *thd);
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);
  bool get_date_internal(MYSQL_TIME *ltime);
  void store_timestamp_internal(const struct timeval *tm);
public:
  static const int PACK_LENGTH= 4;
  Field_timestamp(uchar *ptr_arg, uint32 len_arg,
                  uchar *null_ptr_arg, uchar null_bit_arg,
                  enum utype unireg_check_arg, const char *field_name_arg);
  Field_timestamp(bool maybe_null_arg, const char *field_name_arg);
  enum_field_types type() const { return MYSQL_TYPE_TIMESTAMP;}
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_ULONG_INT; }
  type_conversion_status store_packed(longlong nr);
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=ptr[3]=0;
    return TYPE_OK;
  }
  longlong val_int(void);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return PACK_LENGTH; }
  void sql_type(String &str) const;
  bool zero_pack() const { return 0; }
  /* Get TIMESTAMP field value as seconds since begging of Unix Epoch */
  bool get_timestamp(struct timeval *tm, int *warnings);
  bool get_date(MYSQL_TIME *ltime,uint fuzzydate);
  Field_timestamp *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIMESTAMP);
    return new (mem_root) Field_timestamp(*this);
  }
  Field_timestamp *clone() const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIMESTAMP);
    return new Field_timestamp(*this);
  }
  uchar *pack(uchar *to, const uchar *from,
              uint max_length __attribute__((unused)), bool low_byte_first)
  {
    return pack_int32(to, from, low_byte_first);
  }
  const uchar *unpack(uchar* to, const uchar *from,
                      uint param_data __attribute__((unused)),
                      bool low_byte_first)
  {
    return unpack_int32(to, from, low_byte_first);
  }
  /* Validate the value stored in a field */
  virtual type_conversion_status validate_stored_val(THD *thd);
};


/*
  Field implementing TIMESTAMP(N) data type, where N=0..6.
*/
class Field_timestampf :public Field_temporal_with_date_and_timef {
protected:
  bool get_date_internal(MYSQL_TIME *ltime);
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);
  ulonglong date_flags(const THD *thd);
  void store_timestamp_internal(const struct timeval *tm);
public:
  static const int PACK_LENGTH= 8;
  Field_timestampf(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
                   enum utype unireg_check_arg, const char *field_name_arg,
                   uint8 dec_arg);
  Field_timestampf(bool maybe_null_arg, const char *field_name_arg,
                   uint8 dec_arg);
  Field_timestampf *clone(MEM_ROOT *mem_root) const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIMESTAMP);
    return new (mem_root) Field_timestampf(*this);
  }
  Field_timestampf *clone() const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIMESTAMP);
    return new Field_timestampf(*this);
  }

  enum_field_types type() const { return MYSQL_TYPE_TIMESTAMP; }
  enum_field_types real_type() const { return MYSQL_TYPE_TIMESTAMP2; }
  enum_field_types binlog_type() const { return MYSQL_TYPE_TIMESTAMP2; }
  bool zero_pack() const { return 0; }

  uint32 pack_length() const
  {
    return my_timestamp_binary_length(dec);
  }
  virtual uint pack_length_from_metadata(uint field_metadata)
  {
    DBUG_ENTER("Field_timestampf::pack_length_from_metadata");
    uint tmp= my_timestamp_binary_length(field_metadata);
    DBUG_RETURN(tmp);
  }

  type_conversion_status reset();
  type_conversion_status store_packed(longlong nr);
  bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
  void sql_type(String &str) const;

  bool get_timestamp(struct timeval *tm, int *warnings);
  /* Validate the value stored in a field */
  virtual type_conversion_status validate_stored_val(THD *thd);
};


class Field_year :public Field_tiny {
public:
  Field_year(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
             uchar null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg)
    :Field_tiny(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                unireg_check_arg, field_name_arg, 1, 1)
    {}
  enum_field_types type() const { return MYSQL_TYPE_YEAR;}
  type_conversion_status store(const char *to,uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  void sql_type(String &str) const;
  bool can_be_compared_as_longlong() const { return true; }
  Field_year *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_YEAR);
    return new (mem_root) Field_year(*this);
  }
  Field_year *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_YEAR);
    return new Field_year(*this);
  }
};


class Field_newdate :public Field_temporal_with_date {
protected:
  static const int PACK_LENGTH= 3;
  ulonglong date_flags(const THD *thd);
  bool get_date_internal(MYSQL_TIME *ltime);
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);

public:
  Field_newdate(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
                enum utype unireg_check_arg, const char *field_name_arg)
    :Field_temporal_with_date(ptr_arg, null_ptr_arg, null_bit_arg,
                              unireg_check_arg, field_name_arg,
                              MAX_DATE_WIDTH, 0)
    { }
  Field_newdate(bool maybe_null_arg, const char *field_name_arg)
    :Field_temporal_with_date((uchar *) 0, maybe_null_arg ? (uchar *) "" : 0,
                              0, NONE, field_name_arg, MAX_DATE_WIDTH, 0)
    { }
  enum_field_types type() const { return MYSQL_TYPE_DATE;}
  enum_field_types real_type() const { return MYSQL_TYPE_NEWDATE; }
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_UINT24; }
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=0;
    return TYPE_OK;
  }
  type_conversion_status store_packed(longlong nr);
  longlong val_int(void);
  longlong val_time_temporal();
  longlong val_date_temporal();
  String *val_str(String*,String *);
  bool send_binary(Protocol *protocol);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return PACK_LENGTH; }
  void sql_type(String &str) const;
  bool zero_pack() const { return 1; }
  bool get_date(MYSQL_TIME *ltime,uint fuzzydate);
  Field_newdate *clone(MEM_ROOT *mem_root) const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_DATE);
    DBUG_ASSERT(real_type() == MYSQL_TYPE_NEWDATE);
    return new (mem_root) Field_newdate(*this);
  }
  Field_newdate *clone() const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_DATE);
    DBUG_ASSERT(real_type() == MYSQL_TYPE_NEWDATE);
    return new Field_newdate(*this);
  }
};


class Field_time_common :public Field_temporal {
protected:
  bool convert_str_to_TIME(const char *str, uint len, const CHARSET_INFO *cs,
                           MYSQL_TIME *ltime, MYSQL_TIME_STATUS *status);
  type_conversion_status convert_number_to_TIME(longlong nr, bool unsigned_val,
                                                int nanoseconds,
                                                MYSQL_TIME *ltime,
                                                int *warning);
  virtual type_conversion_status store_internal(const MYSQL_TIME *ltime,
                                                int *error)= 0;
  virtual type_conversion_status store_internal_with_round(MYSQL_TIME *ltime,
                                                           int *warnings);
public:
  Field_time_common(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
                    enum utype unireg_check_arg, const char *field_name_arg,
                    uint8 dec_arg)
    :Field_temporal(ptr_arg, null_ptr_arg, null_bit_arg,
                    unireg_check_arg, field_name_arg,
                    MAX_TIME_WIDTH, dec_arg)
    { }
  Field_time_common(bool maybe_null_arg, const char *field_name_arg,
                    uint8 dec_arg)
    :Field_temporal((uchar *) 0, maybe_null_arg ? (uchar *) "" : 0, 0,
                    NONE, field_name_arg, MAX_TIME_WIDTH, dec_arg)
    { }
  type_conversion_status store_time(MYSQL_TIME *ltime, uint8 dec);
  String *val_str(String*, String *);
  bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
  longlong val_date_temporal();
  bool send_binary(Protocol *protocol);
};


/*
  Field implementing TIME data type without fractional seconds.
  We will be removed eventually.
*/
class Field_time :public Field_time_common {
protected:
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);
public:
  Field_time(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg)
    :Field_time_common(ptr_arg, null_ptr_arg, null_bit_arg,
                       unireg_check_arg, field_name_arg, 0)
    { }
  Field_time(bool maybe_null_arg, const char *field_name_arg)
    :Field_time_common((uchar *) 0, maybe_null_arg ? (uchar *) "" : 0, 0,
                       NONE, field_name_arg, 0)
    { }
  enum_field_types type() const { return MYSQL_TYPE_TIME;}
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_INT24; }
  type_conversion_status store_packed(longlong nr);
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=0;
    return TYPE_OK;
  }
  longlong val_int(void);
  longlong val_time_temporal();
  bool get_time(MYSQL_TIME *ltime);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return 3; }
  void sql_type(String &str) const;
  bool zero_pack() const { return 1; }
  Field_time *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIME);
    return new (mem_root) Field_time(*this);
  }
  Field_time *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIME);
    return new Field_time(*this);
  }
};


/*
  Field implementing TIME(N) data type, where N=0..6.
*/
class Field_timef :public Field_time_common {
private:
  int do_save_field_metadata(uchar *metadata_ptr)
  {
    *metadata_ptr= decimals();
    return 1;
  }
protected:
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);
public:
  Field_timef(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
              enum utype unireg_check_arg, const char *field_name_arg,
              uint8 dec_arg)
    :Field_time_common(ptr_arg, null_ptr_arg, null_bit_arg,
                       unireg_check_arg, field_name_arg, dec_arg)
  { }
  Field_timef(bool maybe_null_arg, const char *field_name_arg, uint8 dec_arg)
    :Field_time_common((uchar *) 0, maybe_null_arg ? (uchar *) "" : 0, 0,
                       NONE, field_name_arg, dec_arg)
  { }
  Field_timef *clone(MEM_ROOT *mem_root) const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIME);
    return new (mem_root) Field_timef(*this);
  }
  Field_timef *clone() const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_TIME);
    return new Field_timef(*this);
  }
  uint decimals() const { return dec; }
  enum_field_types type() const { return MYSQL_TYPE_TIME;}
  enum_field_types real_type() const { return MYSQL_TYPE_TIME2; }
  enum_field_types binlog_type() const { return MYSQL_TYPE_TIME2; }
  type_conversion_status store_packed(longlong nr);
  type_conversion_status reset();
  double val_real();
  longlong val_int();
  longlong val_time_temporal();
  bool get_time(MYSQL_TIME *ltime);
  my_decimal *val_decimal(my_decimal *);
  uint32 pack_length() const
  {
    return my_time_binary_length(dec);
  }
  virtual uint pack_length_from_metadata(uint field_metadata)
  {
    DBUG_ENTER("Field_timef::pack_length_from_metadata");
    uint tmp= my_time_binary_length(field_metadata);
    DBUG_RETURN(tmp);
  }
  uint row_pack_length() const { return pack_length(); }
  void sql_type(String &str) const;
  bool zero_pack() const { return 1; }
  const CHARSET_INFO *sort_charset(void) const { return &my_charset_bin; }
  void make_sort_key(uchar *to, uint length) { memcpy(to, ptr, length); }
  int cmp(const uchar *a_ptr, const uchar *b_ptr)
  {
    return memcmp(a_ptr, b_ptr, pack_length());
  }
};


/*
  Field implementing DATETIME data type without fractional seconds.
  We will be removed eventually.
*/
class Field_datetime :public Field_temporal_with_date_and_time {
protected:
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);
  bool get_date_internal(MYSQL_TIME *ltime);
  ulonglong date_flags(const THD *thd);
  void store_timestamp_internal(const struct timeval *tm);

public:
  static const int PACK_LENGTH= 8;

  Field_datetime(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
                 enum utype unireg_check_arg, const char *field_name_arg)
    :Field_temporal_with_date_and_time(ptr_arg, null_ptr_arg, null_bit_arg,
                                       unireg_check_arg, field_name_arg, 0)
    {}
  Field_datetime(bool maybe_null_arg, const char *field_name_arg)
    :Field_temporal_with_date_and_time((uchar *) 0,
                                       maybe_null_arg ? (uchar *) "" : 0,
                                       0, NONE, field_name_arg, 0)
    {}
  enum_field_types type() const { return MYSQL_TYPE_DATETIME;}
#ifdef HAVE_LONG_LONG
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_ULONGLONG; }
#endif
  using Field_temporal_with_date_and_time::store; // Make -Woverloaded-virtual
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status store_packed(longlong nr);
  type_conversion_status reset(void)
  {
    ptr[0]=ptr[1]=ptr[2]=ptr[3]=ptr[4]=ptr[5]=ptr[6]=ptr[7]=0;
    return TYPE_OK;
  }
  longlong val_int(void);
  String *val_str(String*,String *);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return PACK_LENGTH; }
  void sql_type(String &str) const;
  bool zero_pack() const { return 1; }
  bool get_date(MYSQL_TIME *ltime,uint fuzzydate);
  Field_datetime *clone(MEM_ROOT *mem_root) const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_DATETIME);
    return new (mem_root) Field_datetime(*this);
  }
  Field_datetime *clone() const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_DATETIME);
    return new Field_datetime(*this);
  }
  uchar *pack(uchar* to, const uchar *from,
              uint max_length __attribute__((unused)), bool low_byte_first)
  {
    return pack_int64(to, from, low_byte_first);
  }
  const uchar *unpack(uchar* to, const uchar *from,
                      uint param_data __attribute__((unused)),
                      bool low_byte_first)
  {
    return unpack_int64(to, from, low_byte_first);
  }
};


/*
  Field implementing DATETIME(N) data type, where N=0..6.
*/
class Field_datetimef :public Field_temporal_with_date_and_timef {
protected:
  bool get_date_internal(MYSQL_TIME *ltime);
  type_conversion_status store_internal(const MYSQL_TIME *ltime, int *error);
  ulonglong date_flags(const THD *thd);
  void store_timestamp_internal(const struct timeval *tm);

public:
  Field_datetimef(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
                 enum utype unireg_check_arg, const char *field_name_arg,
                 uint8 dec_arg)
    :Field_temporal_with_date_and_timef(ptr_arg, null_ptr_arg, null_bit_arg,
                                        unireg_check_arg, field_name_arg,
                                        dec_arg)
    {}
  Field_datetimef(bool maybe_null_arg, const char *field_name_arg,
                  uint8 dec_arg)
    :Field_temporal_with_date_and_timef((uchar *) 0,
                                        maybe_null_arg ? (uchar *) "" : 0, 0,
                                        NONE, field_name_arg, dec_arg)
    {}
  Field_datetimef *clone(MEM_ROOT *mem_root) const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_DATETIME);
    return new (mem_root) Field_datetimef(*this);
  }
  Field_datetimef *clone() const
  {
    DBUG_ASSERT(type() == MYSQL_TYPE_DATETIME);
    return new Field_datetimef(*this);
  }

  enum_field_types type() const { return MYSQL_TYPE_DATETIME;}
  enum_field_types real_type() const { return MYSQL_TYPE_DATETIME2; }
  enum_field_types binlog_type() const { return MYSQL_TYPE_DATETIME2; }
  uint32 pack_length() const
  {
    return my_datetime_binary_length(dec);
  }
  virtual uint pack_length_from_metadata(uint field_metadata)
  {
    DBUG_ENTER("Field_datetimef::pack_length_from_metadata");
    uint tmp= my_datetime_binary_length(field_metadata);
    DBUG_RETURN(tmp);
  }
  bool zero_pack() const { return 1; }

  type_conversion_status store_packed(longlong nr);
  type_conversion_status reset();
  longlong val_date_temporal();
  bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
  void sql_type(String &str) const;
};


class Field_string :public Field_longstr {
public:
  bool can_alter_field_type;
  Field_string(uchar *ptr_arg, uint32 len_arg,uchar *null_ptr_arg,
               uchar null_bit_arg,
               enum utype unireg_check_arg, const char *field_name_arg,
               const CHARSET_INFO *cs)
    :Field_longstr(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                   unireg_check_arg, field_name_arg, cs),
     can_alter_field_type(1) {};
  Field_string(uint32 len_arg,bool maybe_null_arg, const char *field_name_arg,
               const CHARSET_INFO *cs)
    :Field_longstr((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "": 0, 0,
                   NONE, field_name_arg, cs),
     can_alter_field_type(1) {};

  enum_field_types type() const
  {
    return ((can_alter_field_type && orig_table &&
             orig_table->s->db_create_options & HA_OPTION_PACK_RECORD &&
             field_length >= 4) &&
            orig_table->s->frm_version < FRM_VER_TRUE_VARCHAR ?
            MYSQL_TYPE_VAR_STRING : MYSQL_TYPE_STRING);
  }
  bool match_collation_to_optimize_range() const { return true; }
  enum ha_base_keytype key_type() const
    { return binary() ? HA_KEYTYPE_BINARY : HA_KEYTYPE_TEXT; }
  bool zero_pack() const { return 0; }
  type_conversion_status reset(void)
  {
    charset()->cset->fill(charset(),(char*) ptr, field_length,
                          (has_charset() ? ' ' : 0));
    return TYPE_OK;
  }
  type_conversion_status store(const char *to,uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(longlong nr, bool unsigned_val);
  /* QQ: To be deleted */
  type_conversion_status store(double nr) { return Field_str::store(nr); }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  my_decimal *val_decimal(my_decimal *);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  void sql_type(String &str) const;
  virtual uchar *pack(uchar *to, const uchar *from,
                      uint max_length, bool low_byte_first);
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first);
  uint pack_length_from_metadata(uint field_metadata)
  {
    DBUG_PRINT("debug", ("field_metadata: 0x%04x", field_metadata));
    if (field_metadata == 0)
      return row_pack_length();
    return (((field_metadata >> 4) & 0x300) ^ 0x300) + (field_metadata & 0x00ff);
  }
  bool compatible_field_size(uint field_metadata, Relay_log_info *rli,
                             uint16 mflags, int *order_var);
  uint row_pack_length() const { return field_length; }
  int pack_cmp(const uchar *a,const uchar *b,uint key_length,
               my_bool insert_or_update);
  int pack_cmp(const uchar *b,uint key_length,my_bool insert_or_update);
  uint packed_col_length(const uchar *to, uint length);
  uint max_packed_col_length(uint max_length);
  enum_field_types real_type() const { return MYSQL_TYPE_STRING; }
  bool has_charset(void) const
  { return charset() == &my_charset_bin ? FALSE : TRUE; }
  Field *new_field(MEM_ROOT *root, TABLE *new_table, bool keep_type);
  Field_string *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(real_type() == MYSQL_TYPE_STRING);
    return new (mem_root) Field_string(*this);
  }
  Field_string *clone() const {
    DBUG_ASSERT(real_type() == MYSQL_TYPE_STRING);
    return new Field_string(*this);
  }
  virtual uint get_key_image(uchar *buff,uint length, imagetype type);
private:
  int do_save_field_metadata(uchar *first_byte);
};


class Field_varstring :public Field_longstr {
public:
  /*
    The maximum space available in a Field_varstring, in bytes. See
    length_bytes.
  */
  static const uint MAX_SIZE;
  /* Store number of bytes used to store length (1 or 2) */
  uint32 length_bytes;
  Field_varstring(uchar *ptr_arg,
                  uint32 len_arg, uint length_bytes_arg,
                  uchar *null_ptr_arg, uchar null_bit_arg,
                  enum utype unireg_check_arg, const char *field_name_arg,
                  TABLE_SHARE *share, const CHARSET_INFO *cs)
    :Field_longstr(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                   unireg_check_arg, field_name_arg, cs),
     length_bytes(length_bytes_arg)
  {
    share->varchar_fields++;
  }
  Field_varstring(uint32 len_arg,bool maybe_null_arg,
                  const char *field_name_arg,
                  TABLE_SHARE *share, const CHARSET_INFO *cs)
    :Field_longstr((uchar*) 0,len_arg, maybe_null_arg ? (uchar*) "": 0, 0,
                   NONE, field_name_arg, cs),
     length_bytes(len_arg < 256 ? 1 :2)
  {
    share->varchar_fields++;
  }

  enum_field_types type() const { return MYSQL_TYPE_VARCHAR; }
  bool match_collation_to_optimize_range() const { return true; }
  enum ha_base_keytype key_type() const;
  uint row_pack_length() const { return field_length; }
  bool zero_pack() const { return 0; }
  type_conversion_status reset(void)
  {
    memset(ptr, 0, field_length+length_bytes);
    return TYPE_OK;
  }
  uint32 pack_length() const { return (uint32) field_length+length_bytes; }
  uint32 key_length() const { return (uint32) field_length; }
  uint32 sort_length() const
  {
    return (uint32) field_length + (field_charset == &my_charset_bin ?
                                    length_bytes : 0);
  }
  type_conversion_status store(const char *to,uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(longlong nr, bool unsigned_val);
  /* QQ: To be deleted */
  type_conversion_status store(double nr) { return Field_str::store(nr); }
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  my_decimal *val_decimal(my_decimal *);
  int cmp_max(const uchar *, const uchar *, uint max_length);
  int cmp(const uchar *a,const uchar *b)
  {
    return cmp_max(a, b, ~0L);
  }
  void make_sort_key(uchar *buff, uint length);
  uint get_key_image(uchar *buff,uint length, imagetype type);
  void set_key_image(const uchar *buff,uint length);
  void sql_type(String &str) const;
  virtual uchar *pack(uchar *to, const uchar *from,
                      uint max_length, bool low_byte_first);
  virtual const uchar *unpack(uchar* to, const uchar *from,
                              uint param_data, bool low_byte_first);
  int cmp_binary(const uchar *a,const uchar *b, uint32 max_length=~0L);
  int key_cmp(const uchar *,const uchar*);
  int key_cmp(const uchar *str, uint length);
  uint packed_col_length(const uchar *to, uint length);
  uint max_packed_col_length(uint max_length);
  uint32 data_length();
  enum_field_types real_type() const { return MYSQL_TYPE_VARCHAR; }
  bool has_charset(void) const
  { return charset() == &my_charset_bin ? FALSE : TRUE; }
  Field *new_field(MEM_ROOT *root, TABLE *new_table, bool keep_type);
  Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
                       uchar *new_ptr, uchar *new_null_ptr,
                       uint new_null_bit);
  Field_varstring *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_VARCHAR);
    DBUG_ASSERT(real_type() == MYSQL_TYPE_VARCHAR);
    return new (mem_root) Field_varstring(*this);
  }
  Field_varstring *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_VARCHAR);
    DBUG_ASSERT(real_type() == MYSQL_TYPE_VARCHAR);
    return new Field_varstring(*this);
  }
  uint is_equal(Create_field *new_field);
  void hash(ulong *nr, ulong *nr2);
private:
  int do_save_field_metadata(uchar *first_byte);
};


class Field_blob :public Field_longstr {
  virtual type_conversion_status store_internal(const char *from, uint length,
                                                const CHARSET_INFO *cs);
  type_conversion_status store_to_mem(const char *from, uint length,
                                      const CHARSET_INFO *cs,
                                      uint max_length,
                                      Blob_mem_storage *blob_storage);
protected:
  uint packlength;
  
  String value;

  void store_ptr_and_length(const char *from, uint32 length)
  {
    store_length(length);
    bmove(ptr + packlength, &from, sizeof(char *));
  }
  
public:
  Field_blob(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg,
             TABLE_SHARE *share, uint blob_pack_length, const CHARSET_INFO *cs);
  Field_blob(uint32 len_arg,bool maybe_null_arg, const char *field_name_arg,
             const CHARSET_INFO *cs)
    :Field_longstr((uchar*) 0, len_arg, maybe_null_arg ? (uchar*) "": 0, 0,
                   NONE, field_name_arg, cs),
    packlength(4)
  {
    flags|= BLOB_FLAG;
  }
  Field_blob(uint32 len_arg,bool maybe_null_arg, const char *field_name_arg,
             const CHARSET_INFO *cs, bool set_packlength)
    :Field_longstr((uchar*) 0,len_arg, maybe_null_arg ? (uchar*) "": 0, 0,
                   NONE, field_name_arg, cs)
  {
    flags|= BLOB_FLAG;
    packlength= 4;
    if (set_packlength)
    {
      uint32 l_char_length= len_arg/cs->mbmaxlen;
      packlength= l_char_length <= 255 ? 1 :
                  l_char_length <= 65535 ? 2 :
                  l_char_length <= 16777215 ? 3 : 4;
    }
  }
  Field_blob(uint32 packlength_arg)
    :Field_longstr((uchar*) 0, 0, (uchar*) "", 0, NONE, "temp", system_charset_info),
    packlength(packlength_arg) {}
  /* Note that the default copy constructor is used, in clone() */
  enum_field_types type() const { return MYSQL_TYPE_BLOB;}
  bool match_collation_to_optimize_range() const { return true; }
  enum ha_base_keytype key_type() const
    { return binary() ? HA_KEYTYPE_VARBINARY2 : HA_KEYTYPE_VARTEXT2; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*,String *);
  my_decimal *val_decimal(my_decimal *);
  int cmp_max(const uchar *, const uchar *, uint max_length);
  int cmp(const uchar *a,const uchar *b)
    { return cmp_max(a, b, ~0L); }
  int cmp(const uchar *a, uint32 a_length, const uchar *b, uint32 b_length);
  int cmp_binary(const uchar *a,const uchar *b, uint32 max_length=~0L);
  int key_cmp(const uchar *,const uchar*);
  int key_cmp(const uchar *str, uint length);
  uint32 key_length() const { return 0; }
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const
  { return (uint32) (packlength + portable_sizeof_char_ptr); }

  uint32 pack_length_no_ptr() const
  { return (uint32) (packlength); }
  uint row_pack_length() const { return pack_length_no_ptr(); }
  uint32 sort_length() const;
  virtual uint32 max_data_length() const
  {
    return (uint32) (((ulonglong) 1 << (packlength*8)) -1);
  }
  type_conversion_status reset(void)
  {
    memset(ptr, 0, packlength+sizeof(uchar*));
    return TYPE_OK;
  }
  void reset_fields() { memset(&value, 0, sizeof(value)); }
  uint32 get_field_buffer_size(void) { return value.alloced_length(); }
#ifndef WORDS_BIGENDIAN
  static
#endif
  void store_length(uchar *i_ptr, uint i_packlength, uint32 i_number, bool low_byte_first);
  void store_length(uchar *i_ptr, uint i_packlength, uint32 i_number)
  {
    store_length(i_ptr, i_packlength, i_number, table->s->db_low_byte_first);
  }
  inline void store_length(uint32 number)
  {
    store_length(ptr, packlength, number);
  }

  uint32 get_packed_size(const uchar *ptr_arg, bool low_byte_first)
    {return packlength + get_length(ptr_arg, packlength, low_byte_first);}

  inline uint32 get_length(uint row_offset= 0)
  { return get_length(ptr+row_offset, this->packlength, table->s->db_low_byte_first); }
  uint32 get_length(const uchar *ptr, uint packlength, bool low_byte_first);
  uint32 get_length(const uchar *ptr_arg)
  { return get_length(ptr_arg, this->packlength, table->s->db_low_byte_first); }
  void put_length(uchar *pos, uint32 length);
  inline void get_ptr(uchar **str)
    {
      memcpy(str, ptr+packlength, sizeof(uchar*));
    }
  inline void get_ptr(uchar **str, uint row_offset)
    {
      memcpy(str, ptr+packlength+row_offset, sizeof(char*));
    }
  inline void set_ptr(uchar *length, uchar *data)
    {
      memcpy(ptr,length,packlength);
      memcpy(ptr+packlength, &data,sizeof(char*));
    }
  void set_ptr_offset(my_ptrdiff_t ptr_diff, uint32 length, uchar *data)
    {
      uchar *ptr_ofs= ADD_TO_PTR(ptr,ptr_diff,uchar*);
      store_length(ptr_ofs, packlength, length);
      memcpy(ptr_ofs+packlength, &data, sizeof(char*));
    }
  inline void set_ptr(uint32 length, uchar *data)
    {
      set_ptr_offset(0, length, data);
    }
  uint get_key_image(uchar *buff,uint length, imagetype type);
  void set_key_image(const uchar *buff,uint length);
  void sql_type(String &str) const;
  inline bool copy()
  {
    uchar *tmp;
    get_ptr(&tmp);
    if (value.copy((char*) tmp, get_length(), charset()))
    {
      Field_blob::reset();
      return 1;
    }
    tmp=(uchar*) value.ptr();
    memcpy(ptr+packlength, &tmp, sizeof(char*));
    return 0;
  }
  Field_blob *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_BLOB);
    return new (mem_root) Field_blob(*this);
  }
  Field_blob *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_BLOB);
    return new Field_blob(*this);
  }
  virtual uchar *pack(uchar *to, const uchar *from,
                      uint max_length, bool low_byte_first);
  virtual const uchar *unpack(uchar *to, const uchar *from,
                              uint param_data, bool low_byte_first);
  uint packed_col_length(const uchar *col_ptr, uint length);
  uint max_packed_col_length(uint max_length);
  void free() { value.free(); }
  inline void clear_temporary() { memset(&value, 0, sizeof(value)); }
  friend type_conversion_status field_conv(Field *to,Field *from);
  bool has_charset(void) const
  { return charset() == &my_charset_bin ? FALSE : TRUE; }
  uint32 max_display_length();
  uint32 char_length();
  uint is_equal(Create_field *new_field);
  inline bool in_read_set() { return bitmap_is_set(table->read_set, field_index); }
  inline bool in_write_set() { return bitmap_is_set(table->write_set, field_index); }
private:
  int do_save_field_metadata(uchar *first_byte);
};


#ifdef HAVE_SPATIAL
class Field_geom :public Field_blob {
  virtual type_conversion_status store_internal(const char *from, uint length,
                                                const CHARSET_INFO *cs);
public:
  enum geometry_type geom_type;

  Field_geom(uchar *ptr_arg, uchar *null_ptr_arg, uint null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg,
             TABLE_SHARE *share, uint blob_pack_length,
             enum geometry_type geom_type_arg)
     :Field_blob(ptr_arg, null_ptr_arg, null_bit_arg, unireg_check_arg, 
                 field_name_arg, share, blob_pack_length, &my_charset_bin)
  { geom_type= geom_type_arg; }
  Field_geom(uint32 len_arg,bool maybe_null_arg, const char *field_name_arg,
             TABLE_SHARE *share, enum geometry_type geom_type_arg)
    :Field_blob(len_arg, maybe_null_arg, field_name_arg, &my_charset_bin)
  { geom_type= geom_type_arg; }
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_VARBINARY2; }
  enum_field_types type() const { return MYSQL_TYPE_GEOMETRY; }
  bool match_collation_to_optimize_range() const { return false; }
  void sql_type(String &str) const;
  using Field_blob::store;
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status store_decimal(const my_decimal *);

  type_conversion_status reset(void)
  {
    type_conversion_status res= Field_blob::reset();
    if (res != TYPE_OK)
      return res;
    return maybe_null() ? TYPE_OK : TYPE_ERR_NULL_CONSTRAINT_VIOLATION;
  }

  geometry_type get_geometry_type() { return geom_type; };
  Field_geom *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(type() == MYSQL_TYPE_GEOMETRY);
    return new (mem_root) Field_geom(*this);
  }
  Field_geom *clone() const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_GEOMETRY);
    return new Field_geom(*this);
  }
  uint is_equal(Create_field *new_field);
};
#endif /*HAVE_SPATIAL*/


class Field_enum :public Field_str {
protected:
  uint packlength;
public:
  TYPELIB *typelib;
  Field_enum(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
             uchar null_bit_arg,
             enum utype unireg_check_arg, const char *field_name_arg,
             uint packlength_arg,
             TYPELIB *typelib_arg,
             const CHARSET_INFO *charset_arg)
    :Field_str(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
               unireg_check_arg, field_name_arg, charset_arg),
    packlength(packlength_arg),typelib(typelib_arg)
  {
    flags|=ENUM_FLAG;
  }
  Field *new_field(MEM_ROOT *root, TABLE *new_table, bool keep_type);
  enum_field_types type() const { return MYSQL_TYPE_STRING; }
  bool match_collation_to_optimize_range() const { return false; }
  enum Item_result cmp_type () const { return INT_RESULT; }
  enum Item_result cast_to_int_type () const { return INT_RESULT; }
  enum ha_base_keytype key_type() const;
  type_conversion_status store(const char *to,uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  double val_real(void);
  my_decimal *val_decimal(my_decimal *decimal_value);
  longlong val_int(void);
  String *val_str(String*,String *);
  int cmp(const uchar *,const uchar *);
  void make_sort_key(uchar *buff, uint length);
  uint32 pack_length() const { return (uint32) packlength; }
  void store_type(ulonglong value);
  void sql_type(String &str) const;
  enum_field_types real_type() const { return MYSQL_TYPE_ENUM; }
  uint pack_length_from_metadata(uint field_metadata)
  { return (field_metadata & 0x00ff); }
  uint row_pack_length() const { return pack_length(); }
  virtual bool zero_pack() const { return 0; }
  bool optimize_range(uint idx, uint part) { return 0; }
  bool eq_def(Field *field);
  bool has_charset(void) const { return TRUE; }
  /* enum and set are sorted as integers */
  CHARSET_INFO *sort_charset(void) const { return &my_charset_bin; }
  Field_enum *clone(MEM_ROOT *mem_root) const {
    DBUG_ASSERT(real_type() == MYSQL_TYPE_ENUM);
    return new (mem_root) Field_enum(*this);
  }
  Field_enum *clone() const { 
    DBUG_ASSERT(real_type() == MYSQL_TYPE_ENUM);
    return new Field_enum(*this);
  }
  virtual uchar *pack(uchar *to, const uchar *from,
                      uint max_length, bool low_byte_first);
  virtual const uchar *unpack(uchar *to, const uchar *from,
                              uint param_data, bool low_byte_first);

private:
  int do_save_field_metadata(uchar *first_byte);
  uint is_equal(Create_field *new_field);
};


class Field_set :public Field_enum {
public:
  Field_set(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
            uchar null_bit_arg,
            enum utype unireg_check_arg, const char *field_name_arg,
            uint32 packlength_arg,
            TYPELIB *typelib_arg, const CHARSET_INFO *charset_arg)
    :Field_enum(ptr_arg, len_arg, null_ptr_arg, null_bit_arg,
                    unireg_check_arg, field_name_arg,
                packlength_arg,
                typelib_arg,charset_arg),
      empty_set_string("", 0, charset_arg)
    {
      flags= (flags & ~ENUM_FLAG) | SET_FLAG;
    }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr)
  {
    return Field_set::store((longlong) nr, FALSE);
  }
  type_conversion_status store(longlong nr, bool unsigned_val);
  virtual bool zero_pack() const { return 1; }
  String *val_str(String*,String *);
  void sql_type(String &str) const;
  enum_field_types real_type() const { return MYSQL_TYPE_SET; }
  bool has_charset(void) const { return TRUE; }
  Field_set *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(real_type() == MYSQL_TYPE_SET);
    return new (mem_root) Field_set(*this);
  }
  Field_set *clone() const {
    DBUG_ASSERT(real_type() == MYSQL_TYPE_SET);
    return new Field_set(*this);
  }
private:
  const String empty_set_string;
};


/*
  Note:
    To use Field_bit::cmp_binary() you need to copy the bits stored in
    the beginning of the record (the NULL bytes) to each memory you
    want to compare (where the arguments point).

    This is the reason:
    - Field_bit::cmp_binary() is only implemented in the base class
      (Field::cmp_binary()).
    - Field::cmp_binary() currenly use pack_length() to calculate how
      long the data is.
    - pack_length() includes size of the bits stored in the NULL bytes
      of the record.
*/
class Field_bit :public Field {
public:
  uchar *bit_ptr;     // position in record where 'uneven' bits store
  uchar bit_ofs;      // offset to 'uneven' high bits
  uint bit_len;       // number of 'uneven' high bits
  uint bytes_in_rec;
  Field_bit(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
            uchar null_bit_arg, uchar *bit_ptr_arg, uchar bit_ofs_arg,
            enum utype unireg_check_arg, const char *field_name_arg);
  enum_field_types type() const { return MYSQL_TYPE_BIT; }
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_BIT; }
  uint32 key_length() const { return (uint32) (field_length + 7) / 8; }
  uint32 max_data_length() const { return (field_length + 7) / 8; }
  uint32 max_display_length() { return field_length; }
  Item_result result_type () const { return INT_RESULT; }
  type_conversion_status reset(void)
  {
    memset(ptr, 0, bytes_in_rec);
    if (bit_ptr && (bit_len > 0))  // reset odd bits among null bits
      clr_rec_bits(bit_ptr, bit_ofs, bit_len);
    return TYPE_OK;
  }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr);
  type_conversion_status store(longlong nr, bool unsigned_val);
  type_conversion_status store_decimal(const my_decimal *);
  double val_real(void);
  longlong val_int(void);
  String *val_str(String*, String *);
  virtual bool str_needs_quotes() { return TRUE; }
  my_decimal *val_decimal(my_decimal *);
  int cmp(const uchar *a, const uchar *b)
  {
    DBUG_ASSERT(ptr == a || ptr == b);
    if (ptr == a)
      return Field_bit::key_cmp(b, bytes_in_rec+test(bit_len));
    else
      return Field_bit::key_cmp(a, bytes_in_rec+test(bit_len)) * -1;
  }
  int cmp_binary_offset(uint row_offset)
  { return cmp_offset(row_offset); }
  int cmp_max(const uchar *a, const uchar *b, uint max_length);
  int key_cmp(const uchar *a, const uchar *b)
  { return cmp_binary((uchar *) a, (uchar *) b); }
  int key_cmp(const uchar *str, uint length);
  int cmp_offset(uint row_offset);
  void get_image(uchar *buff, uint length, const CHARSET_INFO *cs)
  { get_key_image(buff, length, itRAW); }   
  void set_image(const uchar *buff,uint length, const CHARSET_INFO *cs)
  { Field_bit::store((char *) buff, length, cs); }
  uint get_key_image(uchar *buff, uint length, imagetype type);
  void set_key_image(const uchar *buff, uint length)
  { Field_bit::store((char*) buff, length, &my_charset_bin); }
  void make_sort_key(uchar *buff, uint length)
  { get_key_image(buff, length, itRAW); }
  uint32 pack_length() const { return (uint32) (field_length + 7) / 8; }
  uint32 pack_length_in_rec() const { return bytes_in_rec; }
  uint pack_length_from_metadata(uint field_metadata);
  uint row_pack_length() const
  { return (bytes_in_rec + ((bit_len > 0) ? 1 : 0)); }
  bool compatible_field_size(uint metadata, Relay_log_info *rli,
                             uint16 mflags, int *order_var);
  void sql_type(String &str) const;
  virtual uchar *pack(uchar *to, const uchar *from,
                      uint max_length, bool low_byte_first);
  virtual const uchar *unpack(uchar *to, const uchar *from,
                              uint param_data, bool low_byte_first);
  virtual void set_default();

  Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
                       uchar *new_ptr, uchar *new_null_ptr,
                       uint new_null_bit);
  void set_bit_ptr(uchar *bit_ptr_arg, uchar bit_ofs_arg)
  {
    bit_ptr= bit_ptr_arg;
    bit_ofs= bit_ofs_arg;
  }
  bool eq(Field *field)
  {
    return (Field::eq(field) &&
            bit_ptr == ((Field_bit *)field)->bit_ptr &&
            bit_ofs == ((Field_bit *)field)->bit_ofs);
  }
  uint is_equal(Create_field *new_field);
  void move_field_offset(my_ptrdiff_t ptr_diff)
  {
    Field::move_field_offset(ptr_diff);
    bit_ptr= ADD_TO_PTR(bit_ptr, ptr_diff, uchar*);
  }
  void hash(ulong *nr, ulong *nr2);
  Field_bit *clone(MEM_ROOT *mem_root) const { 
    DBUG_ASSERT(type() == MYSQL_TYPE_BIT);
    return new (mem_root) Field_bit(*this);
  }
  Field_bit *clone() const {
    DBUG_ASSERT(type() == MYSQL_TYPE_BIT);
    return new Field_bit(*this);
  }
private:
  virtual size_t do_last_null_byte() const;
  int do_save_field_metadata(uchar *first_byte);
};


class Field_bit_as_char: public Field_bit {
public:
  Field_bit_as_char(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
                    uchar null_bit_arg,
                    enum utype unireg_check_arg, const char *field_name_arg);
  enum ha_base_keytype key_type() const { return HA_KEYTYPE_BINARY; }
  type_conversion_status store(const char *to, uint length,
                               const CHARSET_INFO *charset);
  type_conversion_status store(double nr) { return Field_bit::store(nr); }
  type_conversion_status store(longlong nr, bool unsigned_val)
  { return Field_bit::store(nr, unsigned_val); }
  void sql_type(String &str) const;
  Field_bit_as_char *clone(MEM_ROOT *mem_root) const { 
    return new (mem_root) Field_bit_as_char(*this);
  }
  Field_bit_as_char *clone() const { return new Field_bit_as_char(*this); }
};


/*
  Create field class for CREATE TABLE
*/

class Create_field :public Sql_alloc
{
public:
  const char *field_name;
  const char *change;                   // If done with alter table
  const char *after;                    // Put column after this one
  LEX_STRING comment;                   // Comment for field

  Item *def;
  enum  enum_field_types sql_type;
  /*
    At various stages in execution this can be length of field in bytes or
    max number of characters. 
  */
  ulong length;
  /*
    The value of `length' as set by parser: is the number of characters
    for most of the types, or of bytes for BLOBs or numeric types.
  */
  uint32 char_length;
  uint  decimals, flags, pack_length, key_length;
  Field::utype unireg_check;
  TYPELIB *interval;                    // Which interval to use
  TYPELIB *save_interval;               // Temporary copy for the above
                                        // Used only for UCS2 intervals
  List<String> interval_list;
  const CHARSET_INFO *charset;
  Field::geometry_type geom_type;
  Field *field;                         // For alter table

  uint8 row,col,sc_length,interval_id;  // For rea_create_table
  uint  offset,pack_flag;
  Create_field() :after(NULL) {}
  Create_field(Field *field, Field *orig_field);
  /* Used to make a clone of this object for ALTER/CREATE TABLE */
  Create_field *clone(MEM_ROOT *mem_root) const
    { return new (mem_root) Create_field(*this); }
  void create_length_to_internal_length(void);

  /* Init for a tmp table field. To be extended if need be. */
  void init_for_tmp_table(enum_field_types sql_type_arg,
                          uint32 max_length, uint32 decimals,
                          bool maybe_null, bool is_unsigned,
                          uint pack_length = ~0U);

  bool init(THD *thd, char *field_name, enum_field_types type, char *length,
            char *decimals, uint type_modifier, Item *default_value,
            Item *on_update_value, LEX_STRING *comment, char *change,
            List<String> *interval_list, const CHARSET_INFO *cs,
            uint uint_geom_type);

  bool field_flags_are_binary()
  {
    return (flags & (BINCMP_FLAG | BINARY_FLAG)) != 0;
  }

  ha_storage_media field_storage_type() const
  {
    return (ha_storage_media)
      ((flags >> FIELD_FLAGS_STORAGE_MEDIA) & 3);
  }

  column_format_type column_format() const
  {
    return (column_format_type)
      ((flags >> FIELD_FLAGS_COLUMN_FORMAT) & 3);
  }
};


/*
  A class for sending info to the client
*/

class Send_field :public Sql_alloc {
 public:
  const char *db_name;
  const char *table_name,*org_table_name;
  const char *col_name,*org_col_name;
  ulong length;
  uint charsetnr, flags, decimals;
  enum_field_types type;
  Send_field() {}
};


/*
  A class for quick copying data to fields
*/

class Copy_field :public Sql_alloc {
  typedef void Copy_func(Copy_field*);
  Copy_func *get_copy_func(Field *to, Field *from);
public:
  uchar *from_ptr,*to_ptr;
  uchar *from_null_ptr,*to_null_ptr;
  my_bool *null_row;
  uint  from_bit,to_bit;
  uint from_length,to_length;
  Field *from_field,*to_field;
  String tmp;                                   // For items

  Copy_field() {}
  ~Copy_field() {}
  void set(Field *to,Field *from,bool save);    // Field to field 
  void set(uchar *to,Field *from);              // Field to string
  void (*do_copy)(Copy_field *);
  void (*do_copy2)(Copy_field *);               // Used to handle null values
};


Field *make_field(TABLE_SHARE *share, uchar *ptr, uint32 field_length,
                  uchar *null_pos, uchar null_bit,
                  uint pack_flag, enum_field_types field_type,
                  const CHARSET_INFO *cs,
                  Field::geometry_type geom_type,
                  Field::utype unireg_check,
                  TYPELIB *interval, const char *field_name);
uint pack_length_to_packflag(uint type);
enum_field_types get_blob_type_from_length(ulong length);
uint32 calc_pack_length(enum_field_types type,uint32 length);
type_conversion_status set_field_to_null(Field *field);
type_conversion_status set_field_to_null_with_conversions(Field *field,
                                                          bool no_conversions);

/*
  The following are for the interface with the .frm file
*/

#define FIELDFLAG_DECIMAL               1
#define FIELDFLAG_BINARY                1       // Shares same flag
#define FIELDFLAG_NUMBER                2
#define FIELDFLAG_ZEROFILL              4
#define FIELDFLAG_PACK                  120     // Bits used for packing
#define FIELDFLAG_INTERVAL              256     // mangled with decimals!
#define FIELDFLAG_BITFIELD              512     // mangled with decimals!
#define FIELDFLAG_BLOB                  1024    // mangled with decimals!
#define FIELDFLAG_GEOM                  2048    // mangled with decimals!

#define FIELDFLAG_TREAT_BIT_AS_CHAR     4096    /* use Field_bit_as_char */

#define FIELDFLAG_LEFT_FULLSCREEN       8192
#define FIELDFLAG_RIGHT_FULLSCREEN      16384
#define FIELDFLAG_FORMAT_NUMBER         16384   // predit: ###,,## in output
#define FIELDFLAG_NO_DEFAULT            16384   /* sql */
#define FIELDFLAG_SUM                   ((uint) 32768)// predit: +#fieldflag
#define FIELDFLAG_MAYBE_NULL            ((uint) 32768)// sql
#define FIELDFLAG_HEX_ESCAPE            ((uint) 0x10000)
#define FIELDFLAG_PACK_SHIFT            3
#define FIELDFLAG_DEC_SHIFT             8
#define FIELDFLAG_MAX_DEC               31
#define FIELDFLAG_NUM_SCREEN_TYPE       0x7F01
#define FIELDFLAG_ALFA_SCREEN_TYPE      0x7800

#define MTYP_TYPENR(type) (type & 127)  /* Remove bits from type */

#define f_is_dec(x)             ((x) & FIELDFLAG_DECIMAL)
#define f_is_num(x)             ((x) & FIELDFLAG_NUMBER)
#define f_is_zerofill(x)        ((x) & FIELDFLAG_ZEROFILL)
#define f_is_packed(x)          ((x) & FIELDFLAG_PACK)
#define f_packtype(x)           (((x) >> FIELDFLAG_PACK_SHIFT) & 15)
#define f_decimals(x)           ((uint8) (((x) >> FIELDFLAG_DEC_SHIFT) & FIELDFLAG_MAX_DEC))
#define f_is_alpha(x)           (!f_is_num(x))
#define f_is_binary(x)          ((x) & FIELDFLAG_BINARY) // 4.0- compatibility
#define f_is_enum(x)            (((x) & (FIELDFLAG_INTERVAL | FIELDFLAG_NUMBER)) == FIELDFLAG_INTERVAL)
#define f_is_bitfield(x)        (((x) & (FIELDFLAG_BITFIELD | FIELDFLAG_NUMBER)) == FIELDFLAG_BITFIELD)
#define f_is_blob(x)            (((x) & (FIELDFLAG_BLOB | FIELDFLAG_NUMBER)) == FIELDFLAG_BLOB)
#define f_is_geom(x)            (((x) & (FIELDFLAG_GEOM | FIELDFLAG_NUMBER)) == FIELDFLAG_GEOM)
#define f_is_equ(x)             ((x) & (1+2+FIELDFLAG_PACK+31*256))
#define f_settype(x)            (((int) x) << FIELDFLAG_PACK_SHIFT)
#define f_maybe_null(x)         (x & FIELDFLAG_MAYBE_NULL)
#define f_no_default(x)         (x & FIELDFLAG_NO_DEFAULT)
#define f_bit_as_char(x)        ((x) & FIELDFLAG_TREAT_BIT_AS_CHAR)
#define f_is_hex_escape(x)      ((x) & FIELDFLAG_HEX_ESCAPE)

#endif /* FIELD_INCLUDED */