创建外键及主键
--创建主键
create table t1(
nid int(11) not null auto_increment,
pid int(11),
num int(11),
primary key(nid,pid)
) engine=innodb default charset=utf8;
--创建外键
create table t2(
id int auto_increment primary key,
name char(10),
id1 int,
id2 int,
constraint fk_t2_t1 foreign key(id1,id2) references t1(nid,pid)
) engine=innodb default charset=utf8;