table1 table2
id numb conb id
1 2 2 1
2 3 4 1
3 1
查询的结果为
id numb conb
1 2 2
4
3
请问如何写查询语句
------解决方案--------------------
- SQL code
if object_id('tb1') is not null drop table tb1gocreate table tb1(id int,numb int)insert into tb1 values(1,2)insert into tb1 values(2,3)if object_id('tb2') is not null drop table tb2gocreate table tb2(id int,conb int)insert into tb2 values(1,2)insert into tb2 values(1,3)insert into tb2 values(1,4)select tb1.*,tb2.conb from tb1 right join tb2 on tb2.id=tb1.id and tb1.numb =tb2.conbid numb conb----------- ----------- -----------1 2 2NULL NULL 3NULL NULL 4(3 行受影响)
------解决方案--------------------
- SQL code
if object_id('tb1') is not null drop table tb1gocreate table tb1(id varchar(10),numb varchar(10))insert into tb1 values(1,2)insert into tb1 values(2,3)if object_id('tb2') is not null drop table tb2gocreate table tb2(id int,conb int)insert into tb2 values(1,2)insert into tb2 values(1,3)insert into tb2 values(1,4)select isnull(a.id,'') id,isnull(a.numb,'') numb,b.conb from tb1 a right join tb2 b on a.id=b.id and a.numb =b.conbid numb conb---------- ---------- -----------1 2 2 3 4
------解决方案--------------------