A column in the database table is described by its type and further data according to the type. These data are passed in the variant structure t_specif:
union t_specif
{ tobjnum domain_num;
struct
{ sig8 scale;
uns8 precision;
};
struct
{ uns16 length;
uns8 charset;
uns8 ignore_case : 1;
uns8 wide_char : 2;
};
};
The cd_Enum_attributes_ex and cd_Attribute_info_ex function return this structure and the SQL_host_execute or SQL_host_prepare require this structure. The individual items of this structure have the following meaning:
| Item | Usage for types | Meaning |
| domain_num | Domains | Domain type object number |
| scale | Accurate numeric types | Number of decimal places |
| precision | Accurate numeric types | Approximate number of valid digits |
| length | Character and binary strings with limited length | Length (maximum length) |
| charset | Character strings | Charset code |
| ignore_case | Character strings | A flag specifying whether to keep in mind letter case when comparing |
| wide_char | Character strings | 16-bit characters flag (unicode, i.e. NCHAR type) |