NULLIF
NULLIF ( <value-expression>, <value-expression> )
Returns null if the two input arguments are equal, otherwise returns the first value. Both arguments must be of comparable type, or an exception is raised.
Examples
| Function | Result |
|---|---|
|
NULLIF(4,2) |
4 |
|
NULLIF(4,4) |
<null> |
|
NULLIF('amy','fred') |
amy |
|
NULLIF('amy', cast(null as varchar(3))) |
amy |
|
NULLIF(cast(null as varchar(3)),'fred') |
<null> |
