FLOOR

description

Syntax

T floor(T x[, d])

If not specified d: returns the largest integer value less than or equal to x, which is the most common usage. Otherwise, returns the largest round number that is less than or equal to x and flowing the rules:

If d is specified as literal:
d = 0: just like without d d > 0 or d < 0: the round number would be a multiple of 1/(10^d), or the nearest number of the appropriate data type if 1/(10^d) isn't exact.

Else if d is a column, and x has Decimal type, scale of result Decimal will always be same with input Decimal.

:::tip Another alias for this function is dfloor. :::

example

mysql> select floor(1);
+------------+
| floor(1.0) |
+------------+
|          1 |
+------------+
mysql> select floor(2.4);
+------------+
| floor(2.4) |
+------------+
|          2 |
+------------+
mysql> select floor(-10.3);
+--------------+
| floor(-10.3) |
+--------------+
|          -11 |
+--------------+
mysql> select floor(123.45, 1), floor(123.45), floor(123.45, 0), floor(123.45, -1);
+------------------+---------------+------------------+-------------------+
| floor(123.45, 1) | floor(123.45) | floor(123.45, 0) | floor(123.45, -1) |
+------------------+---------------+------------------+-------------------+
|            123.4 |           123 |              123 |               120 |
+------------------+---------------+------------------+-------------------+
mysql> SELECT number
    -> , floor(number * 2.5, number - 1) AS f_decimal_column
    -> , floor(number * 2.5, 0) AS f_decimal_literal
    -> , floor(cast(number * 2.5 AS DOUBLE), number - 1) AS f_double_column
    -> , floor(cast(number * 2.5 AS DOUBLE), 0) AS f_double_literal
    -> FROM test_enhanced_round
    -> WHERE rid = 1;
+--------+------------------+-------------------+-----------------+------------------+
| number | f_decimal_column | f_decimal_literal | f_double_column | f_double_literal |
+--------+------------------+-------------------+-----------------+------------------+
|      1 |              2.0 |                 2 |               2 |                2 |
+--------+------------------+-------------------+-----------------+------------------+

keywords

FLOOR, DFLOOR

EXP GREATEST