Question

我想知道你们是否可以帮助我在单一查询中简化以下查询。

我有10个查询，就像下面的查询一样。所有这些之间的唯一区别是字段“Outcoming Task”，以1开头，直到10。

SELECT 
S1.[Main Project] AS Company, 
S1.[Main Link] AS Project, 
S1.[Name] AS Milestone, 
S1.[Start] AS MilestoneDueDate, 
S2.[Name] AS Successor, 
S2.[Start] AS SuccessorDueDate

FROM Sheet1 AS S1 INNER JOIN Sheet1 AS S2 ON S1.[Outcoming Task 1] = S2.[ID]

WHERE 
S1.Start >S2.[Start] AND 
S1.[%compl#] <> 100 AND 
(S1.[Task class] <> '***Sammelvorgang' AND S1.[Task class] <> '' AND  S1.[Task class] <> 'M D-Muster') AND 
(S2.[Task class] <> '***Sammelvorgang' AND S2.[Task class] <> '' AND  S2.[Task class] <> 'M D-Muster')

ORDER BY 
S1.[Main Project], 
S1.[Main Link], 
S1.[Name];

我创建它的原因是因为DBA而不是为任务之间的连接创建表，创建了10个字段，如Outcoming Task 1，Outcoming Task 2和Outcoming Task 3 ...

是否可以将所有查询合并为一个？你们能给我一个关于如何做的小费吗？

信息： MS-ACCESS 2010

谢谢，

Answer 1

尝试类似下面的查询。我还认为，列名中的空格不是最佳实践。

SELECT 
    S1.[Main Project] AS Company, 
    S1.[Main Link] AS Project, 
    S1.[Name] AS Milestone, 
    S1.[Start] AS MilestoneDueDate, 
    S2.[Name] AS Successor_Task1, 
    S2.[Start] AS SuccessorDueDate_Task1,

    S3.[Name] AS Successor_Task2, 
    S3.[Start] AS SuccessorDueDate_Task2,   

    ... 3, 4, 5, 6, 7, 8, 9, 10 ...

FROM 
    Sheet1 AS S1 
    LEFT JOIN Sheet1 AS S2 
        ON S1.[Outcoming Task 1] = S2.[ID]

    LEFT JOIN Sheet1 AS S3
        ON S1.[Outcoming Task 2] = S3.[ID]

    ... 3, 4, 5, 6, 7, 8, 9, 10 ...

WHERE 
    S1.Start >S2.[Start] AND 
    S1.[%compl#] <> 100 AND 
    (S1.[Task class] <> '***Sammelvorgang' AND S1.[Task class] <> '' AND  S1.[Task class] <> 'M D-Muster') AND 
    (S2.[Task class] <> '***Sammelvorgang' AND S2.[Task class] <> '' AND  S2.[Task class] <> 'M D-Muster') AND

    (S3.[Task class] <> '***Sammelvorgang' AND S3.[Task class] <> '' AND  S3.[Task class] <> 'M D-Muster')

    ... 3, 4, 5, 6, 7, 8, 9, 10 ...

ORDER BY 
    S1.[Main Project], 
    S1.[Main Link], 
    S1.[Name];

Answer 2

听起来好像你想要一个UNION查询。这是一个简单的例子：

假设你有两张桌子

<强> [表1]
[ID]自动编号
[输出任务1]数字（长整数）
[Outcoming Task 2] Numeric（Long Integer）

带数据

ID  Outcoming Task 1  Outcoming Task 2  
--  ----------------  ----------------  
1   1                 2  
2   1                 3

<强> [任务]
[ID]自动编号
[TaskName]文字（255）

带数据

ID  TaskName
--  --------
1   Task1
2   Task2
3   Task3

查询

SELECT t1.[ID], 1 AS [Outcoming Task], t.[TaskName]
FROM [Table1] t1 INNER JOIN [Tasks] t ON t.[ID] = t1.[Outcoming Task 1]
UNION
SELECT t1.[ID], 2 AS [Outcoming Task], t.[TaskName]
FROM [Table1] t1 INNER JOIN [Tasks] t ON t.[ID] = t1.[Outcoming Task 2]

将产生

ID  Outcoming Task  TaskName
--  --------------  --------
1   1               Task1
1   2               Task2
2   1               Task1
2   2               Task3

使用多列简化SQL查询

2 个答案: