摘要:
create table a ( id varchar(20) primary key, password varchar(20) not null )create table b ( id int identity(1,1) primary key, name varchar(50) not null, userId varchar(20), foreign key (userId) references a(id) on delete cascade ) 表B创建了外码userId 对应A的主码ID,声明了级联删除 测试数据: insert a values ('11',&
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