# NULLIF
<a name="sql-reference-nullif"></a>

```
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
<a name="sql-reference-nullif-examples"></a>


| 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>  |