SQL Server查询分解表

Question

不知道它是如何调用，我需要这样做：

+---------------+ 
| param | value | 
| 1 | 3 | 
| 1 | 3 | 
| 2 | 4 | 
| 2 | 4 | 
+-------+-------+ 

到

+-----------------+ 
| param1 | param2 | 
| 3 | 4 | 
| 3 | 4 | 
+-------+---------+ 

是否有可能不INNER JOIN？

我的错误在哪里？

SELECT TOP 10 
    dbo.RW_ReceivedData.[Value] AS Value1, 
    dbo.RW_ReceivedData.[Value] AS Value2 
FROM 
    RW_ReceivedData 
WHERE 
    dbo.RW_ReceivedData.LogicalName = CAST(0x01000F0800FF AS varbinary(8000)), 
    dbo.RW_ReceivedData.LogicalName = CAST(0x01000F0800FF AS varbinary(8000)) 

Answer 1

这应该工作：

DECLARE @cols NVARCHAR(4000) 
= STUFF(
    (
     SELECT DISTINCT ',[' + CAST(param AS VARCHAR(10)) + ']' 
     FROM tbl 
     FOR XML PATH('') 
    ),1,1,'') 

DECLARE @colNames NVARCHAR(4000) 
= STUFF(
    (
     SELECT DISTINCT ',[' + CAST(param AS VARCHAR(10)) + '] AS param' + CAST(param AS VARCHAR(10)) 
     FROM tbl 
     FOR XML PATH('') 
    ),1,1,'') 

DECLARE @sql NVARCHAR(4000) = 
' 
SELECT '+@colNames+' 
FROM  
(
    SELECT *, ROW_NUMBER() OVER (PARTITION BY param ORDER BY param) n 
    FROM tbl 
) t 
PIVOT 
(
    MIN(value) FOR param IN ('+@cols+') 
) pvt' 

EXEC(@sql) 

这里是SQL Fiddle

这种方法使用动态PIVOT。为了得到预期的结果ROW_NUMBER()与分区被使用，因为param列中的值不是唯一的。

UPDATE

你也可以尝试一下这样的，但是你必须手动添加列查询：

SELECT SUM(CASE WHEN param = 1 THEN value ELSE 0 END) param1 
     , SUM(CASE WHEN param = 2 THEN value ELSE 0 END) param2 
     , SUM(CASE WHEN param = 3 THEN value ELSE 0 END) param3 
FROM 
    (
     SELECT * 
       , ROW_NUMBER() OVER (PARTITION BY param ORDER BY param) num 
     FROM tbl 
    ) t 
GROUP BY 
     num 

SQL Fiddle

如果你不想自动处理色谱柱，只需使用静态PIVOT：

SELECT [1] AS param1 
     ,[2] AS param2 
FROM (  
    SELECT * 
      , ROW_NUMBER() OVER (PARTITION BY param ORDER BY param) n  
    FROM tbl) t 
PIVOT (  
    MIN(value) FOR param IN ([1],[2]) 
) pvt