Table-level constraint

[CONSTRAINT constraint-Name]
{
    CHECK (searchCondition) |
    {
        PRIMARY KEY ( Simple-column-Name [ , Simple-column-Name ]* ) |
        UNIQUE ( Simple-column-Name [ , Simple-column-Name ]* ) |
        FOREIGN KEY ( Simple-column-Name [ , Simple-column-Name ]* )
            REFERENCES clause
    }
}