Example: Querying for a Phone Number
The following example returns the home phone number of the named individual (if present), or office phone if HomePhone is null, or MessageService if present and both home and office phone values are null. Returns NULL if all three values are null.
SELECT Name, COALESCE (HomePhone, OfficePhone, MessageService) FROM PhoneDir;
Example: Using COALESCE with an Arithmetic Operator
The following example uses COALESCE with an arithmetic operator.
SELECT COALESCE(Boxes,0) * 100 FROM Shipments;
Example: Using COALESCE with an Comparison Operator
The following example uses COALESCE with a comparison operator.
SELECT Name FROM Directory WHERE Organization <> COALESCE (Level1, Level2, Level3);