USE nvl for null values in DB

NVL(eExpression1, eExpression2)

eExpression1, eExpression2

NVL( ) returns eExpression2 if eExpression1 evaluates to a null value. NVL( ) returns eExpression1 if eExpression1 is not a null value. eExpression1 and eExpression2 may be any data type. NVL( ) returns .NULL. if both eExpression1 and eExpression2 both evaluate to the null value.

Example: SELECT phone_number, NVL(phone_number, 'MISSING') FROM employees;