如何加入一个查询到另一个查询

我有两个疑问，我想加入与SQL第二，这里是我的查询第一个查询，如何加入一个查询到另一个查询

第一个查询

OleDbCommand Query1 = new OleDbCommand(); 
Query.CommandText = "SELECT [Mastertable].ID " + 
"FROM [Mastertable] INNER JOIN [relationship] ON [Mastertable].ID = [relationship].SW1_ID " + 
"WHERE ([Mastertable].[PN]= @PN AND [Mastertable].[Ver][email protected]) " + 
"GROUP BY [Mastertable].[ID]"; 

DataSet ResultSet = RunQuery(Query1);

以上查询基本恢复，其中PN = PN输入和版本=版本的输入。（我把结果数据集中

我想从QUERY1加入ID列再次

第二查询Mastertable。ID的ID，

OleDbCommand Query2 = new OleDbCommand(); 
Query2.CommandText = "SELECT [Mastertable].PN, [Mastertable].[Ver], [relationship].[Category], [Mastertable].[Component_Name] " + 
"FROM (Query1 INNER JOIN [relationship] ON Query1.[ID] = [relationship].SID) INNER JOIN " + 
"[Mastertable] ON [relationship].SW2_ID = [Mastertable].[ID]"; 

DataSet ResultSet2 = RunQuery(Query2);

但这段代码不起作用，我在网上搜索了很多，并尝试了一些，但他们没有帮助。我想用ResultSet1.Tables [0] .TableName和ResultSet1.Tables [0] .Columns [0] .name和但没有工作=（

请帮

来源

2014-02-07 DaveZ

我认为最好只使用一个查询。 SQL是加入数据的最佳位置。 – AFetter

解决！感谢大家！ = D – DaveZ

OleDbCommand Query2 = new OleDbCommand(); 
Query2.CommandText = "SELECT [SW Mastertable].SW_PN, [SW Mastertable].[SW_Ver], [SW relationship].[SW2_Category]," + 
" [SW Mastertable].[Component_Name] " + 
" FROM " + 
"(SELECT [Mastertable].ID as ID " + 
"FROM [Mastertable] INNER JOIN [relationship] ON [Mastertable].ID = [relationship].SW1_ID " + 
"WHERE ([Mastertable].[PN]= @PN AND [Mastertable].[Ver][email protected]) " + 
"GROUP BY [Mastertable].[ID]) as Query1 " + 
" INNER JOIN [SW relationship] ON Query1.[ID] = [SW relationship].SW1_ID INNER JOIN " + 
"[SW Mastertable] ON [SW relationship].SW2_ID = [SW Mastertable].[ID]"; 

DataSet ResultSet2 = RunQuery(Query2);

来源

2014-02-07 05:11:56 jainvikram444

是的！非常感谢！有效。感谢您向我展示如何使用AS Query1 – DaveZ

你可以加入查询1到第二（外）QUERY2作为派生表如下：

SELECT [SW Mastertable].SW_PN, [SW Mastertable].[SW_Ver], 
     [SW relationship].[SW2_Category], [SW Mastertable].[Component_Name] 
FROM 
    (SELECT [Mastertable].ID 
    FROM [Mastertable] 
     INNER JOIN [relationship] ON [Mastertable].ID = [relationship].SW1_ID 
    WHERE ([Mastertable].[PN]= @PN AND [Mastertable].[Ver][email protected]) 
    GROUP BY [Mastertable].[ID] 
) Query1 
    INNER JOIN [SW relationship] ON Query1.[ID] = [SW relationship].SW1_ID) 
    INNER JOIN [SW Mastertable] ON [SW relationship].SW2_ID = [SW Mastertable].[ID];

如果您正在使用sql-server你也可以做到这一点的CTE：

WITH Query1 AS 
(
    SELECT [Mastertable].ID 
    FROM [Mastertable] 
     INNER JOIN [relationship] ON [Mastertable].ID = [relationship].SW1_ID 
    WHERE ([Mastertable].[PN]= @PN AND [Mastertable].[Ver][email protected]) 
    GROUP BY [Mastertable].[ID] 
) 
SELECT [SW Mastertable].SW_PN, [SW Mastertable].[SW_Ver], 
     [SW relationship].[SW2_Category], [SW Mastertable].[Component_Name] 
FROM 
    Query1 
    INNER JOIN [SW relationship] ON Query1.[ID] = [SW relationship].SW1_ID) 
    INNER JOIN [SW Mastertable] ON [SW relationship].SW2_ID = [SW Mastertable].[ID];

来源

2014-02-07 05:00:51 StuartLC

这是SQL。操作正在使用asp.net –

OP明确指出'加入第一个查询与第二个SQL' – StuartLC

我添加了“AS Query1 INNER JOIN [SW Relation]”而不是“Query1 INNER JOIN [SW Relation]”并且它工作正常！谢谢 – DaveZ

不是很确定这是否会工作但你仍然可以试试看。如果有的话，请修复语法错误。

此外，我假设你有Query1对象可用（即不是空或不超出范围），同时尝试创建Query2对象。

OleDbCommand Query2 = new OleDbCommand(); 
Query2.CommandText = "SELECT [SW Mastertable].SW_PN, [SW Mastertable].[SW_Ver], [SW relationship].[SW2_Category], [SW Mastertable].[Component_Name], [SW relationship].SW2_ID " + 
"FROM (("+ Query1.CommandText +")TAB1 INNER JOIN [SW relationship] ON TAB1.[ID] = [SW relationship].SW1_ID) TAB2 INNER JOIN " + 
"[SW Mastertable] ON [TAB2].SW2_ID = [SW Mastertable].[ID]"; 

DataSet ResultSet2 = RunQuery(Query2);

希望这会有所帮助。

来源

2014-02-07 05:02:49 samar

如何加入一个查询到另一个查询

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