ADD CONSTRAINT 절

설명

ADD CONSTRAINT 절을 사용하여 새로운 제약 조건을 추가할 수 있다.

구문

ALTER [ TABLE | CLASS | VCLASS | VIEW ] table_name

ADD CONSTRAINT < constraint_name > column_constraint ( index_column_name )

 

column_constraint ::=

UNIQUE [ KEY ] |

PRIMARY KEY |

FOREIGN KEY REFERENCES [referenced_table_name]( column_name_comma_list )

                       [ <referential_triggered_action> ... ]

 

<referential_triggered_action> ::=

{ ON UPDATE <referential_action> } |

{ ON DELETE <referential_action> } |

{ ON CACHE OBJECT cache_object_column_name }

 

<referential_action> ::=

CASCADE | RESTRICT | NO ACTION | SET NULL

예제

ALTER TABLE a_tbl ADD CONSTRAINT PRIMARY KEY(id);

ALTER TABLE a_tbl ADD CONSTRAINT UNIQUE u_key1(id);