Oracle/PLSQL: IS NULL

In PLSQL to check if a value is null, you must use the "IS NULL" syntax.

For example,

IF Lvalue IS NULL then

   ...

END IF;

If Lvalue contains a null value, the "IF" expression will evaluate to TRUE.

You can also use "IS NULL" in an SQL statement. For example:

select * from suppliers
where supplier_name IS NULL;

This will return all records from the suppliers table where the supplier_name contains a null value.