NULLIF

Compares two expressions. If the values in each expression are equal, returns NULL and, if they are not equal, returns the value of the first expression.

Syntax

NULLIF(expression1, expression2) → same as input type

  • expression: The expressions can be any data type, however all the expressions contained in the argument must be of the same type.

Examples

NULLIF example
SELECT NULLIF(user_id, customer_id)

-- user_id

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