如何加入 table 与选择性重复记录？ (oracle10g)

Question

如何为以下要求创建 ORACLE 查询？

问题是，如果SQL个结果中存在相同的ID，如何获取Name不为空或NULL的那个ID的记录。

Pattern(1)
SQL1 => RESULT1 =>    ID     NAME
                     -----  ------
                      001
                      002
                      003

SQL2 => RESULT2 =>    ID     NAME
                     -----  ------
                      003    NAME1

SQL3 => RESULT3 =>    ID     NAME
                     -----  ------
                      003    NAME2

Pattern(2)
SQL1 => RESULT1 =>    ID     NAME
                     -----  ------
                      001
                      002
                      003    NAME1

SQL2 => RESULT2 =>    ID     NAME
                     -----  ------
                      003    

SQL3 => RESULT3 =>    ID     NAME
                     -----  ------
                      003    NAME2

Pattern(3)
SQL1 => RESULT1 =>    ID     NAME
                     -----  ------
                      001
                      002
                      003   

SQL2 => RESULT2 =>    ID     NAME
                     -----  ------
                      003    NAME1
                      003    NAME2

SQL3 => RESULT3 =>    ID     NAME
                     -----  ------

我怎样才能把这3个结果合并成下面的结果？

                      ID     NAME
                     -----  ------
                      001
                      002
                      003    NAME1
                      003    NAME2

Answer 1

一个选择是 UNION 将 SQL2 和 SQL3 表合并，然后将此结果连接回 SQL1:

SELECT t1.ID, t1.NAME
FROM SQL1 t1 LEFT JOIN
(
    SELECT ID, NAME
    FROM SQL2
    UNION ALL
    SELECT ID, NAME
    FROM SQL3
) t2
    ON t1.ID = t2.ID

Answer 2

这适用于您的场景

with tbl(id,name) as
(query1 
 union all
query2
 union all
query 3
)
select * From tbl where name is null
 and id not in
    (select id from tbl where name is not null)
union all
select * from tbl where name is not null

我已经创建了示例

with tbl(id,name) as
(select 1,null from dual union all
select 2,null from dual union all
select 3,null from dual union all
select 3,'NAME1' from dual union all
select 3,'NAME2' from dual)

select * From tbl where name is null
 and id not in
    (select id from tbl where name is not null)
union all
select * from tbl where name is not null

输出

id  name
---------
1   
2   
3   NAME1
3   NAME2

如何加入 table 与选择性重复记录？ (oracle10g)

How to join table with selective duplicate records? (oracle10g)

sql

oracle

oracle10g