Skip to main content

TRUNC

The TRUNC function is used to truncate a number towards zero, removing the fractional part without rounding. It takes a single floating-point or integer value as its argument and returns a floating-point value.

Syntax​

TRUNC(value)

Examples​

Let's consider a table named SingleItem with the following schema:

CREATE TABLE SingleItem (id INTEGER);

Insert a row into the SingleItem table:

INSERT INTO SingleItem VALUES (0);

Example 1: Using TRUNC function​

SELECT TRUNC(0.3) AS trunc1, TRUNC(-0.8) AS trunc2, TRUNC(10) AS trunc3, TRUNC(6.87421) AS trunc4 FROM SingleItem;

Result:

trunc1 | trunc2 | trunc3 | trunc4
-------+--------+--------+--------
   0.0 |    0.0 |   10.0 |    6.0

Note that the returned values are floating-point numbers, even though they represent integer values. The TRUNC function truncates towards zero, which means:

  • For positive numbers: removes the decimal part (6.87421 → 6.0)
  • For negative numbers: truncates towards zero (-0.8 → 0.0, -1.8 → -1.0)

Errors​

The TRUNC function expects a floating-point or integer value as its argument. Providing any other type, such as a string or boolean, will result in an error.

Example 2: Using TRUNC with a string argument​

SELECT TRUNC('string') AS trunc FROM SingleItem;

Error: Function requires a floating-point or integer value.

Example 3: Using TRUNC with a boolean argument​

SELECT TRUNC(TRUE) AS trunc FROM SingleItem;

Error: Function requires a floating-point or integer value.