class Alter_column_specification

{

public:

  const char *change;                   // If done with alter table

  const char *after;                    // Put column after this one

  Field *field;                         // For alter table

  TYPELIB *save_interval;               // Temporary copy for the above

                                        // Used only for UCS2 intervals

  uint offset;

  uint8 interval_id;                    // For rea_create_table

  bool create_if_not_exists;            // Used in ALTER TABLE IF NOT EXISTS

};

class Column_specification

{

public:

  LEX_STRING comment;

  Item *def, *on_update;

  enum  enum_field_types sql_type;

  ulonglong length;

  uint32 char_length;

  uint  decimals, flags, pack_length, key_length;

  Field::utype unireg_check;

  TYPELIB *interval;

  List<String> interval_list;

  CHARSET_INFO *charset;

  uint32 srid;

  Field::geometry_type geom_type;

  engine_option_value *option_list;

  ha_field_option_struct *option_struct;

  uint  pack_flag;

  Virtual_column_info *vcol_info;

  bool stored_in_db;

};

class Create_field: public Column_specification,

                    public Alter_column_specification,

                    public Sql_alloc

{

public:

  LEX_CSTRING field_name;

};