Oracle/PLSQL: ORA-00908 Error

Error:

ORA-00908: missing NULL keyword

Cause:

You tried to execute an SQL statement, but you missed entering the NULL keyword.

Action:

The options to resolve this Oracle error are:

This error can occur if you try to execute an SQL statement using the IS NULL or IS NOT NULL clause, but miss entering the NULL keyword.

For example, if you tried executing the following statement:

SELECT * FROM suppliers
where supplier_name IS NOT;

You would receive the following error message:

You could correct this error, by modifying the statement as follows:

SELECT * FROM suppliers
where supplier_name IS NOT NULL;