NULLIF

Conditional Function

Description

The NULLIF expression compares two arguments and returns null if the arguments are equal. If they are not equal, the first argument is returned. In Redshift, NULLIF ignores trailing blanks when comparing string values in certain scenarios. As a result, the behavior may differ between Redshift and Snowflake. For this reason, in the transformation RTRIM will add for get the equivalence between Redshift and Snowflake (Redshift SQL Language Reference NULLIF function)

Grammar Syntax

NULLIF ( expression1, expression2 )

This function is fully supported by Snowflake.

Sample Source Patterns

Input Code:

Redshift

IN -> Redshift_01.sql

SELECT NULLIF('first', 'second') AS different, NULLIF('first', 'first') AS same;

Results

different	same
first	NULL

Output Code:

Snowflake

OUT -> Redshift_01.sql

SELECT NULLIF(RTRIM('first'), RTRIM('second')) AS different, NULLIF(RTRIM('first'), RTRIM('first')) AS same;

Results

different	same
first	NULL

Known Issues

There are no known issues.

Related EWIs

There are no known EWIs.