MySQL in a Nutshell

Name

TRUNCATE( )

Synopsis

TRUNCATE(number, number)

This function returns a number given in the first argument with the digits beyond the number of decimal places specified in the second argument, truncated. It does not round the number—use the ROUND( ) function instead. If a 0 is given for the second argument, the decimal point and the fractional value are dropped. If a negative number is given as the second argument, the decimal point and the fractional value is dropped, and the number of positions given is zeroed out for the integer.

SELECT TRUNCATE(321.1234, 2) AS '+2',
       TRUNCATE(321.1234, 0) AS '0',
       TRUNCATE(321.1234, -2) AS '-2';
+--------+-----+-----+
| +2     | 0   | -2  |
+--------+-----+-----+
| 321.12 | 321 | 300 |
+--------+-----+-----+

Notice that for the first field, the last two decimal places are dropped. For the second field, the decimal point and all of the fractional value are dropped. For the third, the decimal point and the fractional value are dropped, and because the second parameter is -2, the first two numbers (starting from the right) of the integer are changed to zeros.