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 |