A field having NULL value is one that has been left blank during record creation, NULL value field means field with no value.

IS NULL

IS NULL operator in SQL is used to test for NULL Values .

Syntax-

SELECT column_name1, column_name2..column_nameN

FROM <table_name>

WHERE<column_name> IS NULL;

IS NOT NULL

IS NOT NULL operators in SQL is used to test for NOT NULL or non-empty values.

Syntax-

SELECT column_name1, column_name2..column_nameN

FROM <table_name>

WHERE<column_name> IS NOT NULL;