有两个表A,B
A
name,category
1 1
2 1
3 1
4 2
5 2
B
fen,name,rq
100 1 2007
我想得到这样的结果:
name,category,fen,rq
1 1 100 2007
2 1 null null
3 1 null null
A
name,category
1 1
2 1
3 1
4 2
5 2
B
fen,name,rq
100 1 2007
我想得到这样的结果:
name,category,fen,rq
1 1 100 2007
2 1 null null
3 1 null null
insert into A values(1, 1 )
insert into A values(2, 1 )
insert into A values(3, 1 )
insert into A values(4, 2 )
insert into A values(5, 2 )
create table B(fen int , name int , rq int)
insert into B values(100, 1 , 2007)
goselect a.* , b.fen , b.rq from a left join b on a.name = b.name where a.category = 1drop table A,B/*
name category fen rq
----------- ----------- ----------- -----------
1 1 100 2007
2 1 NULL NULL
3 1 NULL NULL
(所影响的行数为 3 行)
*/
insert into A values(1, 1 )
insert into A values(2, 1 )
insert into A values(3, 1 )
insert into A values(4, 2 )
insert into A values(5, 2 )
create table B(fen int , name int , rq int)
insert into B values(100, 1 , 2007)
insert into B values(100, 2 , 2003)
goselect a.* , b.fen , b.rq from a left join b on a.name = b.name where a.category = 1drop table A,B/*
name category fen rq
----------- ----------- ----------- -----------
1 1 100 2007
2 1 100 2003
3 1 NULL NULL(所影响的行数为 3 行)
*/