Oracle select 查询语句

[lkyzhm]

A表中字段为
A_ID,B_ID1,B_ID2,ATYPE
1， 1， 2， 1
2， 1， 3， 2
3， ， ，3
4，， 2， 4
5，，，5
6 ，4，， 6

B表中字段为
B_ID,B_NAME
1 LIU
2 KAI
3 AAA
4 BBB
5 CCC
A表中B_ID1，B_ID2都是B表的外键；
我需要的结果为：

A_ID,B_NAME1，B_NAME2，ATYPE
1 ，LIU， KAI， 1
2 ，LIU， AAA， 2
3 ，，，3
4 ，，KAI， 4
5 ，，，5
6， BBB，， 6
语句怎么查询呢？

[changtianshuiyue]

select a.A_ID ,(select b.BNAME from B b where b.B_ID=a.A_ID1),(select b.BNAME from B b where b.B_ID=a.A_ID2) ,a.ATYPE from A a;

[changtianshuiyue]

select a.A_ID ,(select b.BNAME from B b where b.B_ID=a.A_ID1) B_NAME1,(select b.BNAME from B b where b.B_ID=a.A_ID2) B_NAME2,a.ATYPE from A a;

[小海葵1]

with A as
(
select '1' AS A_ID,'1' AS B_ID1,'2' AS B_ID2,'1' AS ATYPE from dual
union all
select '2' AS A_ID,'1' AS B_ID1,'3' AS B_ID2,'2' AS ATYPE from dual
union all
select '3' AS A_ID,' ' AS B_ID1,' ' AS B_ID2,'3' AS ATYPE from dual
union all
select '4' AS A_ID,' ' AS B_ID1,'2' AS B_ID2,'4' AS ATYPE from dual
union all
select '5' AS A_ID,' ' AS B_ID1,' ' AS B_ID2,'5' AS ATYPE from dual
union all
select '6' AS A_ID,'4' AS B_ID1,' ' AS B_ID2,'6' AS ATYPE from dual
),
B AS
(
select '1' AS B_ID,'LIU' AS B_NAME from dual
union all
select '2' AS B_ID,'KAI' AS B_NAME from dual
union all
select '3' AS B_ID,'AAA' AS B_NAME from dual
union all
select '4' AS B_ID,'BBB' AS B_NAME from dual
union all
select '5' AS B_ID,'CCC' AS B_NAME from dual
)

SELECT T1.A_ID,T2.B_NAME,T3.B_NAME,T1.ATYPE FROM A T1 LEFT JOIN B T2 ON T1.B_ID1 = T2.B_ID LEFT JOIN B T3 ON T1.B_ID2 = T3.B_ID ORDER BY T1.A_ID

[長胸為富]

SELECT T1.A_ID,NVL(T2.B_NAME,'') AS ,B_NAME1,NVL(T3.B_NAME,'') AS ,B_NAME2,T1.ATYPE FROM A T1 LEFT JOIN B T2 ON T1.B_ID1 = T2.B_ID LEFT JOIN B T3 ON T1.B_ID2 = T3.B_ID ORDER BY T1.A_ID

[長胸為富]

SELECT T1.A_ID,NVL(T2.B_NAME,'') AS B_NAME1,NVL(T3.B_NAME,'') AS B_NAME2,T1.ATYPE FROM A T1 LEFT JOIN B T2 ON T1.B_ID1 = T2.B_ID LEFT JOIN B T3 ON T1.B_ID2 = T3.B_ID ORDER BY T1.A_ID

[sesunny]

SELECT T1.A_ID,NVL(T2.B_NAME,'') AS ,B_NAME1,NVL(T3.B_NAME,'') AS ,B_NAME2,T1.ATYPE FROM A T1 LEFT JOIN B T2 ON T1.B_ID1 = T2.B_ID LEFT JOIN B T3 ON T1.B_ID2 = T3.B_ID ORDER BY T1.A_ID

[supremeSi]

select A_ID,b1.B_NAME B_NAME1，b2.B_NAME B_NAME2，ATYPE from a,b b1,b b2
where a.B_ID1=b1.B_ID(+)
and a.B_ID2=b2.B_ID(+)

[ssqtjffcu]

with a as(
select 1 a_id,1 b_id1,2 b_id2,1 atype from dual
union all
select 2,1,3,2 from dual
union all
select 3,null,null,3 from dual
union all
select 4,null,2,4 from dual
union all
select 5,null,null,5 from dual
union all
select 6,4,null,6 from dual
),b as(
select 1 b_id,'LIU' b_name from dual
union all
select 2,'KAI' from dual
union all
select 3,'AAA' from dual
union all
select 4,'BBB' from dual
union all
select 5,'CCC' from dual
)
SELECT A_ID,(SELECT B_NAME FROM B WHERE B_ID=A.B_ID1) B_ID1,(SELECT B_NAME FROM B WHERE B_ID=A.B_ID2) B_ID2,ATYPE FROM A
      A_ID B_ID1 B_ID2      ATYPE
---------- ----- ----- ----------
         1 LIU   KAI            1
         2 LIU   AAA            2
         3                      3
         4       KAI            4
         5                      5
         6 BBB                  6
 
6 rows selected

[shuiniu0410]

select table1.a_id,(select table2.b_name from table2 where table1.b_id1=table2.b_id),
(select table2.b_name from table2 where table1.b_id2=table2.b_id),table1.atype
from table1;