将 2 个内部连接结果合并为一个结果答案

【问题标题】：Join 2 inner join result into one result将 2 个内部连接结果合并为一个结果
【发布时间】：2017-12-22 00:05:54
【问题描述】：

大家我有问题。我有两个单独运行良好的查询。但我想提出一个我尝试过的查询，但这些都行不通。我需要加入两个输出。

第一次查询：

SELECT q_internal_table.q_part_id, 
   q_external_table.q_external_id, 
   q_external_table.q_external_approve, 
   q_external_table.q_order_id, 
   q_internal_table.q_internal_id, 
   q_internal_table.q_internal_approve 
   FROM   (SELECT parts.id                  AS q_part_id, 
           parts.order_id            AS q_order_id, 
           external_reports.id       AS q_external_id, 
           external_reports.approved AS q_external_approve 
    FROM   parts 
           INNER JOIN external_reports 
                   ON( parts.id = external_reports.part_id )) 
   q_external_table 
   INNER JOIN (SELECT parts.id                  AS q_part_id, 
                      internal_reports.id       AS q_internal_id, 
                      internal_reports.approved AS q_internal_approve 
               FROM   parts 
                      INNER JOIN internal_reports 
                              ON( parts.id = internal_reports.part_id )) 
          q_internal_table 
           ON( q_external_table.q_part_id = q_internal_table.q_part_id ) 
   WHERE  ( q_external_table.q_external_approve = 'Y' 
      OR q_internal_table.q_internal_approve = 'Y' )

第二次查询：

SELECT q_five_internal_table.q_five_part_id,
   q_five_internal_table.q_five_internal_id, 
   q_five_internal_table.q_five_internal_approve,
   q_five_external_table.q_five_external_id, 
   q_five_external_table.q_five_external_approve, 
   q_five_external_table.q_five_order_id
   FROM   (SELECT parts.id                  AS q_five_part_id, 
           parts.order_id            AS q_five_order_id, 
           five_way_external_reports.id       AS q_five_external_id, 
           five_way_external_reports.approved AS q_five_external_approve 
    FROM   parts 
           INNER JOIN five_way_external_reports 
                   ON( parts.id = five_way_external_reports.part_id )) 
   q_five_external_table 
   INNER JOIN (SELECT parts.id                  AS q_five_part_id, 
                      five_way_internal_reports.id       AS q_five_internal_id, 
                      five_way_internal_reports.approved AS q_five_internal_approve 
               FROM   parts 
                      INNER JOIN five_way_internal_reports 
                              ON( parts.id = five_way_internal_reports.part_id )) 
          q_five_internal_table 
           ON( q_five_external_table.q_five_part_id = q_five_internal_table.q_five_part_id ) 
  WHERE  ( q_five_external_table.q_five_external_approve = 'Y' 
      OR q_five_internal_table.q_five_internal_approve = 'Y' )

第一次查询结果：

第二次查询结果：

我试过这个查询：-

SELECT q_internal_external_table.*, 
   q_five_internal_external_table.* 
FROM   (SELECT q_internal_table.q_part_id, 
           q_external_table.q_external_id, 
           q_external_table.q_external_approve, 
           q_external_table.q_order_id, 
           q_internal_table.q_internal_id, 
           q_internal_table.q_internal_approve 
    FROM  (SELECT parts.id                  AS q_part_id, 
                  parts.order_id            AS q_order_id, 
                  external_reports.id       AS q_external_id, 
                  external_reports.approved AS q_external_approve 
           FROM   parts 
                  INNER JOIN external_reports 
                          ON( parts.id = external_reports.part_id )) 
          q_external_table 
          INNER JOIN (SELECT parts.id                  AS q_part_id, 
                             internal_reports.id       AS q_internal_id, 
                             internal_reports.approved AS q_internal_approve 
                      FROM   parts 
                             INNER JOIN internal_reports 
        ON( parts.id = internal_reports.part_id )) 
        q_internal_table 
       ON( q_external_table.q_part_id = q_internal_table.q_part_id ) 
       WHERE  ( q_external_table.q_external_approve = 'Y' 
       OR q_internal_table.q_internal_approve = 'Y' )) 
       q_internal_external_table 
       INNER JOIN (SELECT q_five_internal_table.q_five_part_id, 
       q_five_internal_table.q_five_internal_id, 
       q_five_internal_table.q_five_internal_approve, 
       q_five_external_table.q_five_order_id, 
       q_five_external_table.q_five_external_id, 
       q_five_external_table.q_five_external_approve 
       FROM   (SELECT parts.id                           AS q_five_part_id, 
       parts.order_id                     AS 
       q_five_order_id 
       , 
      five_way_external_reports.id       AS 
       q_five_external_id, 
       five_way_external_reports.approved AS 
       q_five_external_approve 
       FROM   parts 
       INNER JOIN five_way_external_reports 
       ON( parts.id = five_way_external_reports.part_id )) 
       q_five_external_table 
       INNER JOIN (SELECT parts.id  AS     q_five_part_id, 
       five_way_internal_reports.id       AS 
       q_five_internal_id, 
       five_way_internal_reports.approved AS 
       q_five_internal_approve 
       FROM   parts 
       INNER JOIN five_way_internal_reports 
       ON( parts.id = five_way_internal_reports.part_id )) 
       q_five_internal_table 
       ON ( q_five_external_table.q_five_part_id = 
       q_five_internal_table.q_five_part_id ) 
       WHERE  ( q_five_external_table.q_five_external_approve = 'Y' 
       OR q_five_internal_table.q_five_internal_approve = 'Y' )) 
       q_five_internal_external_table 
       ON ( q_internal_external_table.q_part_id = 
       q_five_internal_external_table.q_five_part_id )

查询结果：- 在这个查询中有三个结果。但我希望 7 结果与第一个查询结果一样。三个答案已经在第一个查询结果中。我也需要休息4。我认为问题出在ON q_internal_external_table.q_part_id = q_five_internal_external_table.q_five_part_id。但是不知道怎么解决。

请帮助我。提前致谢。

【问题讨论】：

1) 预期的结果是什么？ 2) 你尝试过什么，这些尝试出了什么问题？
你的意思是 UNION - 谷歌
@Shadow：我更新了问题。我想加入两个答案。我还添加了我尝试过的 SQL。
类似select * from (1st select) as t1 join (2nd select) as t2 on t1.q_part_id = t2.q_five_part_id.
加入意味着什么？请演示使用问题中已有的 7 + 3 记录。

标签： php mysql sql join mysqli

【解决方案1】：

特别感谢@dnoeth。好人。

修改后的SQL是，

select q_internal_external_table.*,q_five_internal_external_table.* from         
(select q_internal_table.q_part_id, 
q_external_table.q_external_id,q_external_table.q_external_approve, 
q_external_table.q_order_id,q_internal_table.q_internal_id, 
q_internal_table.q_internal_approve from(SELECT parts.id as 
q_part_id,parts.order_id as q_order_id,external_reports.id as 
q_external_id,external_reports.approved as q_external_approve from parts 
LEFT join external_reports on(parts.id=external_reports.part_id)) 
q_external_table LEFT join (SELECT parts.id as q_part_id,internal_reports.id 
as q_internal_id,internal_reports.approved as q_internal_approve from parts 
LEFT join internal_reports on(parts.id=internal_reports.part_id)) 
q_internal_table on(q_external_table.q_part_id=q_internal_table.q_part_id) 
where (q_external_table.q_external_approve='Y' or 
q_internal_table.q_internal_approve='Y')) q_internal_external_table LEFT 
join (select q_five_internal_table.q_five_part_id, 
q_five_internal_table.q_five_internal_id, 
q_five_internal_table.q_five_internal_approve, 
q_five_external_table.q_five_order_id, 
q_five_external_table.q_five_external_id, 
q_five_external_table.q_five_external_approve from (SELECT parts.id as 
q_five_part_id,parts.order_id as q_five_order_id, 
five_way_external_reports.id as q_five_external_id, 
five_way_external_reports.approved as q_five_external_approve from parts 
LEFT join five_way_external_reports on(parts.id= 
five_way_external_reports.part_id)) q_five_external_table LEFT join (SELECT 
parts.id as q_five_part_id,five_way_internal_reports.id as 
q_five_internal_id,five_way_internal_reports.approved as 
q_five_internal_approve from parts LEFT join five_way_internal_reports 
on(parts.id=five_way_internal_reports.part_id)) q_five_internal_table on 
(q_five_external_table.q_five_part_id=q_five_internal_table.q_five_part_id) 
where (q_five_external_table.q_five_external_approve='Y' or 
q_five_internal_table.q_five_internal_approve='Y')) 
q_five_internal_external_table on (q_internal_external_table.q_part_id 
=q_five_internal_external_table.q_five_part_id)

答案：（我想要的）

【讨论】：

【解决方案2】：

如果我们假设您查询的最终目标是在下表中找到一个parts.id，那么您更新后的查询似乎是正确的（语义上）： external_reports，internal_reports，five_way_external_reports，five_way_internal_reports

在合并查询1和查询2的行时使用联合。

但是，如果您尝试查找匹配的列（连接子句），则应使用 JOIN 而不是 UNION。

另外，请尝试在您的查询中添加 EXPLAIN 和 EXPLAIN EXTENDED 前缀以了解查询计划。

【讨论】：

【解决方案3】：

你需要的是UNION。

两个查询需要具有相同数量的列和类型。在您的情况下，您需要更改所选列的顺序以使UNION。

应该是这样的：

SELECT q_internal_table.q_part_id, 
   q_external_table.q_external_id, 
   q_external_table.q_external_approve, 
   q_external_table.q_order_id, 
   q_internal_table.q_internal_id, 
   q_internal_table.q_internal_approve 
   FROM   (SELECT parts.id AS q_part_id, 
           parts.order_id AS q_order_id, 
           external_reports.id AS q_external_id, 
           external_reports.approved AS q_external_approve 
    FROM parts 
           INNER JOIN external_reports 
                   ON( parts.id = external_reports.part_id )) 
   q_external_table 
   INNER JOIN (SELECT parts.id AS q_part_id, 
                      internal_reports.id AS q_internal_id, 
                      internal_reports.approved AS q_internal_approve 
               FROM   parts 
                      INNER JOIN internal_reports 
                              ON( parts.id = internal_reports.part_id )) 
          q_internal_table 
           ON( q_external_table.q_part_id = q_internal_table.q_part_id ) 
   WHERE  ( q_external_table.q_external_approve = 'Y' 
      OR q_internal_table.q_internal_approve = 'Y' )

UNION ALL 

SELECT q_five_internal_table.q_five_part_id,
      q_five_external_table.q_five_external_id,
      q_five_external_table.q_five_external_approve, 
      q_five_external_table.q_five_order_id,
   q_five_internal_table.q_five_internal_id, 
   q_five_internal_table.q_five_internal_approve   
   FROM   (SELECT parts.id AS q_five_part_id, 
           parts.order_id AS q_five_order_id, 
           five_way_external_reports.id AS q_five_external_id, 
           five_way_external_reports.approved AS q_five_external_approve 
    FROM   parts 
           INNER JOIN five_way_external_reports 
                   ON( parts.id = five_way_external_reports.part_id )) 
   q_five_external_table 
   INNER JOIN (SELECT parts.id AS q_five_part_id, 
                      five_way_internal_reports.id AS q_five_internal_id, 
                      five_way_internal_reports.approved AS q_five_internal_approve 
               FROM parts 
                      INNER JOIN five_way_internal_reports 
                              ON( parts.id = five_way_internal_reports.part_id )) 
          q_five_internal_table 
           ON( q_five_external_table.q_five_part_id = q_five_internal_table.q_five_part_id ) 
  WHERE  ( q_five_external_table.q_five_external_approve = 'Y' 
      OR q_five_internal_table.q_five_internal_approve = 'Y' )

请注意，我已更改第二个查询中列的顺序以匹配第一个查询的类型。

【讨论】：

即使知道预期的输出也可能是 UNION 或 EXCEPT 或 INTERSECT :-)
感谢您的帮助。但是在答案中没有显示第二个查询结果。