NULLIF is an advanced function that the Oracle database supports. It is used to compare two expressions. The NULLIF function is supported in the various versions of the Oracle/PLSQL, including, Oracle 12c, Oracle 11g, Oracle 10g and Oracle 9i.
Syntax:
NULLIF( expr1, expr2 )
Parameters:
expr1, expr2: They are used to specify the expressions to compare.
Example 1:
NULLIF (56, 56) |
Output:
NULL
Explanation:
Here, the NULLIF function returns NULL since expr1 and expr2 are equal.
Example 2:
NULLIF (‘apple’, ‘pineapple’) |
Output:
‘apple’
Explanation:
Here, the NULLIF function returns expr1 since expr1 and expr2 are not equal.