要求：
A:a,b,c,d四个字段，
表中数据
aa,aa,aa,aa
bb,bb,bb,bb
cc,cc,cc,cc
dd,dd,dd,dd
B:a,b,r 三个字段
表中数据
aa,aa,a
bb,bb,b
cc,cc,c
dd,dd,b
显示结果：
aa,aa,aa,aa,a
bb,bb,bb,bb,b
cc,cc,cc,cc,c
dd,dd,dd,dd,d
------解决方案--------------------
不知道你表达的意思....
不过下面的语句应该能达到你的效果......
select A.a,A.b,A.c,A.d,B.r from A FULL JOIN B ON A.a=B.a
------解决方案--------------------
A:a,b,c,d四个字段，
表中数据
aa,aa,aa,aa
bb,bb,bb,bb
cc,cc,cc,cc
dd,dd,dd,dd
B:a,b,r 三个字段
表中数据
aa,aa,a
bb,bb,b
cc,cc,c
dd,dd,b
显示结果：
aa,aa,aa,aa,a
bb,bb,bb,bb,b
cc,cc,cc,cc,c
dd,dd,dd,dd,d <---------d怎么来的？B表对应是b
------解决方案--------------------
- SQL code
select ta.a,ta.b,ta.c,ta.d,tb.r from (select 'aa' a,'aa' b,'aa' c,'aa' d from dual union allselect 'bb','bb','bb','bb' from dual union allselect 'cc','cc','cc','cc' from dual union allselect 'dd','dd','dd','dd' from dual ) taleft join (select * from (select 'aa' a,'aa' b,'a' r from dual union allselect 'bb','bb','b' from dual union allselect 'cc','cc','c' from dual union allselect 'dd','dd','d' from dual ) ) tb on ta.a=tb.a and ta.b=tb.b------------------------------------- A B C D R1 aa aa aa aa a2 bb bb bb bb b3 cc cc cc cc c4 dd dd dd dd d