Question

在创建子查询方面需要帮助。

我有两个表“部门访问信息”和“主题代码主表”。如果任何 Dept_code 的访问值为“ALL”，则需要组合这些表。以下是样本信息。

部门访问信息表输入主题代码为“全部”

<头>

部门代码	Subject_Code
101	aa1
102	所有
103	cc1

如果主题代码带有“ALL”，那么我们需要参考主题代码特定表来获取所有主题。例如，对于 Dept_Code，“102”可以访问“所有”主题。

输入类型 -2，Dept_Code 为“ALL”，Subject_Code 为“ALL”

<头>

部门代码	Subject_Code
101	aa1
102	所有
103	cc1
所有	所有

Dept_Code_Master 表包含所有的 Dep_Code |部门代码| |---------| |101 | |102 | |103 | |104 |

学科代码主表

<头>

部门代码	Subject_Code
102	bb1
102	bb2
102	bb3
104	dd1

通过合并101、102和103部门代码最终需要的结果如下：

最终需要的输出：对于 Type-1 输入

<头>

部门代码	Subject_Code
101	aa1
102	bb1
102	bb2
102	bb3
103	cc1

最终要求的输出：类型 2 输入（所有公司，所有账户）

<头>

部门代码	Subject_Code
101	aa1
102	bb1
102	bb2
102	bb3
103	cc1
104	dd1

**** 使用 Input2 编辑

Answer 1

那只是外连接，不是吗？

SELECT          CONCAT(MIN(M.Date), ' to ', MAX(M.Date)) AS DateRange, 
                SUM(M.Discharge) AS TotalDischarge, 
                SUM(M.Conviction) AS TotalConviction, 
                SUM(M.Acquittal) AS TotalAcquittal, 
                SUM(M.Other) AS TotalOther, 
                M.NewCase AS LastNewCase, 
                MP.NewCase AS LastOldCase
FROM            tmp_mytable AS M
    LEFT JOIN   tmp_mytable AS MP ON MP.ID = (SELECT MAX(M2.ID) FROM tmp_mytable AS M2)
WHERE           M.Date BETWEEN '2021-01-01' AND '2021-02-01'

Answer 2

对于您提供的示例，它看起来不需要子查询。

WITH CODE_MASTER AS
  ( SELECT '101' AS Dept_code,
           'aa1' AS Subject_Code
      FROM dual
      UNION
     SELECT '102' AS Dept_code,
           'All' AS Subject_Code
      FROM dual
      UNION
     SELECT '103' AS Dept_code,
           'cc2' AS Subject_Code
      FROM dual
  ),
SUBJECT_CODE_MASTER AS
  ( SELECT '102' AS Dept_code,
           'bb1' AS Subject_Code
      FROM dual
      UNION
     SELECT '102' AS Dept_code,
           'bb2' AS Subject_Code
      FROM dual
      UNION
     SELECT '102' AS Dept_code,
           'bb3' AS Subject_Code
      FROM dual
  )
SELECT CODE_MASTER.DEPT_CODE,
       COALESCE(SUBJECT_CODE_MASTER.subject_code, CODE_MASTER.subject_code) AS Subject_Code
  FROM CODE_MASTER 
  LEFT
  JOIN SUBJECT_CODE_MASTER
    ON CODE_MASTER.dept_code = SUBJECT_CODE_MASTER.dept_code
   AND CODE_MASTER.Subject_Code = 'All'

选择子查询 - 基于值

2 个答案: