PostgreSQL FLOOR() Function

The PostgreSQL FLOOR() function returns a number rounded down to the next whole number.

Syntax

The syntax of the FLOOR() function is as follows:

FLOOR(numeric_expression)

Arguments

The FLOOR() function requires one argument:

1) numeric_expression

The numeric_expression is a number or an expression that evaluates to a number, which you want to round down.

Return Value

The FLOOR() function returns a value whose data type is the same as the input argument.

Examples

The following example shows how to use the FLOOR() function to round a number down to the nearest integer:

SELECT
    FLOOR( 150.75 );

The result is:

150

See the following payment table in the sample database:

The following statement returns the floor of the amount paid by the customer:

SELECT
    customer_id,
    FLOOR(SUM( amount )) amount_paid
FROM
    payment
GROUP BY
    customer_id
ORDER BY
    amount_paid DESC;

The following picture illustrates the result:

Remarks

To round a number up to the nearest whole number, you use the CEIL() function.

In this tutorial, you have learned how to use the PostgreSQL FLOOR() function to round a number down to the nearest integer, which is less than or equal to the number.