what is NULLIF ISNULL

Question

Hi...... what is NULLIF and ISNULL?

Ravi Patel · Answer

Hi NULLIF: NULLIF( expression  expression) It returns a null value if both the expression is equal. NULLIF returns the first expression if both the expression is not equal. ISNULL: ISNULL ( expression  replacement) Replaces NULL with the specified replacement value. It returns the value of expression if it is not null. for more details http://blog.sqlauthority.com/2007/06/22/sql-server-explanation-and-comparison-of-nullif-and-isnull/

what is NULLIF ,ISNULL