SQL语言中把数据库中两张表数据关联起来的语句

Question

cj表
xh
kcdh
cj
kc表
kcdh
kcm
求如何把两张表的内容关联起来（kcdh）的SQL语句

Answer 1

1、创建两张测试表，

create table test_cj(name VARCHAR(20), remark varchar2(20));

create table test_kc(name VARCHAR(20), remark varchar2(20));

2、插入测试数据

insert into test_cj values('xh','cj_1');

insert into test_cj values('kcdh','cj_2');

insert into test_cj values('cj','cj_3');

insert into test_kc values('kcdh','kc_1');

insert into test_kc values('kcm','kc_2');

3、查询两张表的总记录数，select t.*, rowid from test_cj t union all select t.*, rowid from test_kc t，

4、编写sql，两张表进行关联，select t.name, t.remark, b.remark from test_cj t, test_kc b where t.name=b.name，可以发现关联出kcdh的记录，

Answer 2

select *
from cj join kc on cj.kcdh=kc.kcdh

--就这么简单。这样保证两个表的数据都能查出来。
--inner join内连接将会过滤掉不存在关联的数据的。本回答被提问者采纳

Answer 3

select * from cj表,kc表 where cj表.kcdh=kc表.kcdh

或者 select * from cj表 where kcdh=(select kcdh from kc表)

Answer 4

select cj.xh, cj.kcdh, cj.cj, kc.kcdh, kc.kcm
from cj inner join kc on (cj.kcdh = kc.kcdh)
SQL SERVER

PS 用inner join 最好。

Answer 5

Select a.xh,a.kcdh,a.cj,b.kcdh,b.kcm from cj as a,kc as b where a.kcdh=b.kcdh