我想做用户的注册功能(博客)
有用户user表
有国家contrel表
有市city表
有省proveant表
在用户表中有三个外键指向其他三张表
怎么写出一条sql语句当出现国家时后面出现相应的省在后面出现相应的城市
有用户user表
有国家contrel表
有市city表
有省proveant表
在用户表中有三个外键指向其他三张表
怎么写出一条sql语句当出现国家时后面出现相应的省在后面出现相应的城市
调试欢乐多
(select name from contrel where id = t.contrelid),
(select name from city where id = t.cityid),
(select name from proveant where id = t.proveantid)
from [user] t
select t.*,
(select name from contrel where id = t.contrelid),
(select name from city where id = t.cityid),
(select name from proveant where id = t.proveantid)
from [user] t--方法二
select t1.* , t2.name , t3.name , t4.name
from [user] t1
inner join contrel t2 on t1.contrelid = t2.id
inner join city t3 on t1.cityid = t3.id
inner join proveant t4 on t1.proveantid = t4.id
有用户user表
use_id int primary key indentity(1,1)
use_name varchar(20)
fk_contrel int forigen key referenecs contrel(con_id)
fk_city int forigen key referenecs city(cit_id)
fk_proveant int forigen key referenecs contrel(pro_id)
有国家contrel表
con_id int primary key indentity(1,1)
con_name varcher(20)
有市city表
cit_id int primary key indentity(1,1)
cit_name varcher(20)
有省proveant表
pro_id int primary key indentity(1,1)
pro_name varcher(20)
在用户表中有三个外键指向其他三张表
怎么写出一条sql语句当出现国家时后面出现相应的省在后面出现相应的城市
若 中国—四川—成都
select t.*,
(select name from contrel where con_id = t.fk_contrel),
(select name from proveant where pro_id = t.fk_proveant),
(select name from city where cit_id = t.fk_city),
(select name from contrel where con_id = t.fk_contrel)+'-'
(select name from proveant where pro_id = t.fk_proveant)+'-'
(select name from city where cit_id = t.fk_city)
from [user] t--方法二
select t1.* , t2.con_name , t3.pro_name , t4.cit_name , t2.con_name + '-' + t3.pro_name + '-' + t4.cit_name
from [user] t1
inner join contrel t2 on t1.fk_contrel = t2.con_id
inner join proveant t3 on t1.fk_proveant = t3.pro_id
inner join city t4 on t1.fk_city = t4.cit_id