The display size of a column is the maximum number of characters needed to display data in character form. The following table defines the display size for each ODBC SQL data type.
| SQL type identifier | Display size |
| All character types [a] | The defined (for fixed types) or maximum (for variable types) number of characters needed to display the data in character form. |
| SQL_DECIMAL SQL_NUMERIC |
The precision of the column plus 2 (a sign, precision digits, and a decimal point). For example, the display size of a column defined as NUMERIC(10,3) is 12. |
| SQL_BIT | 1 (1 digit). |
| SQL_TINYINT | 4 if signed (a sign and 3 digits) or 3 if unsigned (3 digits). |
| SQL_SMALLINT | 6 if signed (a sign and 5 digits) or 5 if unsigned (5 digits). |
| SQL_INTEGER | 11 if signed (a sign and 10 digits) or 10 if unsigned (10 digits). |
| SQL_BIGINT | 20 (a sign and 19 digits if signed or 20 digits if unsigned). |
| SQL_REAL | 14 (a sign, 7 digits, a decimal point, the letter E, a sign, and 2 digits). |
| SQL_FLOAT SQL_DOUBLE |
24 (a sign, 15 digits, a decimal point, the letter E, a sign, and 3 digits). |
| All binary types [a] | The defined or maximum (for variable types) length of the column times 2 (each binary byte is represented by a 2-digit hexadecimal number). |
| SQL_TYPE_DATE | 10 (a date in the format yyyy-mm-dd). |
| SQL_TYPE_TIME | 8 (a time in the format hh:mm:ss) or 9 + s (a time in the format hh:mm:ss[.fff…], where s is the fractional seconds precision). |
| SQL_TYPE_TIMESTAMP | 19 (for a timestamp in the yyyy-mm-dd hh:mm:ss format) or 20 + s (for a timestamp in the yyyy-mm-dd hh:mm:ss[.fff…] format, where s is the fractional seconds precision). |
| All interval data types | See the “Interval Data Type Length” section earlier in this appendix. |
[a]If the driver cannot determine the column or parameter length of variable types, it returns SQL_NO_TOTAL.