PostgreSQL: trunc Function

This PostgreSQL tutorial explains how to use the PostgreSQL trunc function with syntax and examples.

Description

The PostgreSQL trunc function returns a number truncated to a certain number of decimal places.

Syntax

The syntax for the trunc function in PostgreSQL is:

trunc( number, [ decimal_places ] )

Parameters or Arguments

number

The number to truncate.

decimal_places

Optional. The number of decimal places to truncate to. This value must be a positive or negative integer.

Note

• If decimal_places is a negative number, the trunc function will make digits to the left of the decimal place 0 values.
• See also the round, ceil, ceiling, and floor functions.

Applies To

The trunc function can be used in the following versions of PostgreSQL:

• PostgreSQL 9.4, PostgreSQL 9.3, PostgreSQL 9.2, PostgreSQL 9.1, PostgreSQL 9.0, PostgreSQL 8.4

Example

Let's look at some PostgreSQL trunc function examples and explore how to use the trunc function in PostgreSQL.

For example:

postgres=# SELECT trunc(125.315);
 trunc
-------
   125
(1 row)

postgres=# SELECT trunc(125.315, 0);
 trunc
-------
   125
(1 row)

postgres=# SELECT trunc(125.315, 1);
 trunc
-------
 125.3
(1 row)

postgres=# SELECT trunc(125.315, 2);
 trunc
--------
 125.31
(1 row)

postgres=# SELECT trunc(125.315, -1);
 trunc
-------
   120
(1 row)

postgres=# SELECT trunc(125.315, -2);
 trunc
-------
   100
(1 row)

postgres=# SELECT trunc(-125.315);
 trunc
-------
  -125
(1 row)