COALESCE

  COALESCE ( < - value-expression> {,< - value-expression>}... )

The COALESCE function takes a list of expressions (all of which must be of the same type) and returns the first non-null argument from the list. If all of the expressions are null, COALESCE returns null.

Examples

Expression Result
COALESCE(‘amy’) amy
COALESCE(‘amy’, null, ‘fred’) amy
COALESCE(null, null, ‘fred’) fred
COALESCE(null, 2, 5) 2