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('chair') |
chair |
COALESCE('chair', null, 'sofa') |
chair |
COALESCE(null, null, 'sofa') |
sofa |
COALESCE(null, 2, 5) |
2 |