SQLite nullif() Function

The SQLite nullif() function returns NULL if both parameters are the same, otherwise returns the first argument.

Syntax

Here is the syntax of the SQLite nullif() function:

nullif(expr1, expr2)

Parameters

expr1

Required. A value or expression.

expr2

Required. Another value or expression.

Return value

If the two arguments are the same, expr1 = expr2, the SQLite nullif() function returns NULL, otherwise it returns expr1.

Examples

This example illustrates the ifnull() basic usage of the SQLite function:

SELECT
    nullif(1, 1),
    nullif(1, 2);

nullif(1, 1) =
nullif(1, 2) = 1

nullif() is equivalent to CASE WHEN expr1 = expr2 THEN NULL ELSE expr1 END, as follows:

SELECT
    CASE WHEN 1 = 1 THEN NULL ELSE 1 END,
    CASE WHEN 1 = 2 THEN NULL ELSE 1 END;

CASE WHEN 1 = 1 THEN NULL ELSE 1 END =
CASE WHEN 1 = 2 THEN NULL ELSE 1 END = 1