NULLIF
NULLIF compares one expression with another. It returns NULL when the expressions are equal, or the first expression when they are not.
Return Value
Data type of the first argument
Syntax
NULLIF(expr1, expr2)
Arguments
expr1 is the base expression. It cannot be a literal null.
expr2 is the expression to compare with the base expression.
Example
NULLIF('red', 'Red') returns the value red.
