FLOOR()

Description

The FLOOR() function returns the largest round number that is less than or equal to the number.

Syntax

> FLOOR(number, decimals)
> FLOOR(number)

Arguments

Arguments	Description
number	Required. Any numeric data type supported now.
decimals	Optional. An integer that represents the number of decimal places. By default it is zero, which means to round to an integer. decimals may also be negative.

Examples

drop table if exists t1;
create table t1(a int ,b float);
insert into t1 values(1,0.5);
insert into t1 values(2,0.499);
insert into t1 values(3,0.501);
insert into t1 values(4,20.5);
insert into t1 values(5,20.499);
insert into t1 values(6,13.500);
insert into t1 values(7,-0.500);
insert into t1 values(8,-0.499);
insert into t1 values(9,-0.501);
insert into t1 values(10,-20.499);
insert into t1 values(11,-20.500);
insert into t1 values(12,-13.500);

mysql> select a,floor(b) from t1;
+------+----------+
| a    | floor(b) |
+------+----------+
|    1 |        0 |
|    2 |        0 |
|    3 |        0 |
|    4 |       20 |
|    5 |       20 |
|    6 |       13 |
|    7 |       -1 |
|    8 |       -1 |
|    9 |       -1 |
|   10 |      -21 |
|   11 |      -21 |
|   12 |      -14 |
+------+----------+
12 rows in set (0.01 sec)

mysql> select sum(floor(b)) from t1;
+---------------+
| sum(floor(b)) |
+---------------+
|            -6 |
+---------------+
1 row in set (0.00 sec)

mysql> select a,sum(floor(b)) from t1 group by a order by a;
+------+---------------+
| a    | sum(floor(b)) |
+------+---------------+
|    1 |             0 |
|    2 |             0 |
|    3 |             0 |
|    4 |            20 |
|    5 |            20 |
|    6 |            13 |
|    7 |            -1 |
|    8 |            -1 |
|    9 |            -1 |
|   10 |           -21 |
|   11 |           -21 |
|   12 |           -14 |
+------+---------------+
12 rows in set (0.00 sec)