MySQL 约束求教(页 1) - MySQL

心动音符 发表于 2006-12-23 15:54

MySQL 约束求教

MySQL 支持不支持约束啊我下面写的为什么出错啊大家来指点啊 --add constraints -- add primary key alter table users add constraints users_id_pk primary key(id); alter table user_infos add constraints user_infos_id_pk primary key(id); alter table products add constraints products_id_pk primary key(id); alter table orders add constraints orders_id_pk primary key(id); alter table orderLines add constraints orderLines_id_pk primary key(id); -- add foreign key alter table user_infos add constraints user_info_id_fk foreign key(id) refencese users(id); alter table orders add constraints orders_user_id_fk foreign key(user_id) refencese users(id); alter table orderLines add constraints orderLines_order_id_fk foreign key(order_id) refencese orders(id); alter table orderLines add constraints orderLines_product_id_fk foreign key(procudt_id) refencese product(id); -- add uniue key alter table users add constraints users_login_name unique(login_name); alter table products add constraints products_code unique(code); alter table orders add constraints orders_code unique(code); -- add not null alter table users modify login_name not null; alter table procudts modify code not null; alter table orders modify user_id not null; alter table orders modify code not null; alter table orderLines modify order_id not null; alter table orderLines modify product_id not null; -- add sequence drop sequence my_key; create sequence my_key;

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