ADD check-constraint

CONSTRAINT constraint-name
Names the constraint. A constraint-name must not identify a constraint that already exists at the current server. The constraint-name must be unique within a schema.

If not specified, a unique constraint name is generated by the database manager.

CHECK(check-condition)
Defines a check constraint. The check-condition must be true or unknown for every row of the table.

The check-condition is a search-condition, except:

For more information about search-condition, see Search conditions.