Description of the illustration constraint_clauses.eps

{ ADD { { out_of_line_constraint }...
      | out_of_line_REF_constraint
      }
   | MODIFY { { CONSTRAINT constraint_name [ precheck_state ]
             | PRIMARY KEY
             | UNIQUE (column [, column ]...) }
          constraint_state  [ CASCADE ] }
   | RENAME CONSTRAINT old_name TO new_name
   | { drop_constraint_clause }...
}