ORACLE/PLSQL: NULLIF FUNCTION
This Oracle tutorial explains how to use the Oracle/PLSQL NULLIF function with syntax and examples.
DESCRIPTION
The Oracle/PLSQL NULLIF function compares expr1 and expr2. If expr1 and expr2 are equal, the NULLIF function returns NULL. Otherwise, it returns expr1.
SYNTAX
The syntax for the NULLIF function in Oracle/PLSQL is:
NULLIF( expr1, expr2 )
Parameters or Arguments
expr1
First value to compare. Must be either a numeric value or a value that is the same datatype as expr2.
expr2
Second value to compare. Must be either a numeric value or a value that is the same datatype as expr1.
Note:
expr1 can be an expression that evaluates to NULL, but it can not be the literal NULL.
APPLIES TO
The NULLIF function can be used in the following versions of Oracle/PLSQL:
Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i
EXAMPLE
Let's look at some Oracle NULLIF function examples and explore how to use the NULLIF function in Oracle/PLSQL.
For example:
NULLIF(12, 12)
Result: NULL
NULLIF(12, 13)
Result: 12
NULLIF('apples', 'apples')
Result: NULL
NULLIF('apples', 'oranges')
Result: 'apples'
NULLIF(NULL, 12)
Result: ORA-00932 error (because expr1 can not be the literal NULL)
