Create dynamic select get value for column name -

问题:

Please help me create a select SQL statement with the results column name get from the column values in origin table (tablename is Device_Part):

User can input many DeviceCode which have many dynamic PartTypeName, the PartTypeName value is the PartInfo.

回答1:

This may help:

CREATE Table Device (
DeviceCode NVARCHAR(100) NOT NULL,
PartTypeName NVARCHAR(100) NOT NULL,
PartInfo NVARCHAR(100) NOT NULL
)

Insert Into Device
Values('VT.SX-01','CPU','Pentium G6650'),
('VT.SX-01','Motherboard','H81M -  S2PV'),
('VT.SX-01','RAM','DDR# 4GB - bus 1866 - Nano'),
('VT.SX-01','PartType Name 01','PartInfo 01')

--QUERY
DECLARE @DynamicPivotQuery AS NVARCHAR(MAX);
DECLARE @ColumnNamesInPivot AS NVARCHAR(MAX);

--Get distinct values of PIVOT Column 
SELECT   @ColumnNamesInPivot = ISNULL(@ColumnNamesInPivot + ',', '')
        + QUOTENAME([PartTypeName])
FROM    ( SELECT    DISTINCT
                    [PartTypeName]
          FROM      Device
        ) AS P



SELECT  @DynamicPivotQuery = N'Select DeviceCode,'
        + @ColumnNamesInPivot + ' 
            FROM    ( SELECT * 
          FROM      Device
        ) AS SourceTable PIVOT( MAX(PartInfo) FOR [PartTypeName] IN ('
        + @ColumnNamesInPivot + ') ) AS PVTTable'

EXEC sp_executesql @DynamicPivotQuery;

And the result will be:

回答2:

Try this

;WITH _CTE(_DeviceCode,_PartTypeName,_PartInfo,_Id)
AS
(
 SELECT DeviceCode,PartTypeName,PartInfo ,ROW_NUMBER() OVER (PARTITION BY      PartTypeName ORDER BY Id) FROM Your_tablename
)
SELECT *
FROM
(
SELECT _DeviceCode,_PartTypeName,_PartInfo
FROM _CTE
)C
PIVOT
(
 MAX(_PartInfo) FOR _PartTypeName IN ([CPU],[MotherBoard],[RAM],[PartTypeName])
) AS PivotTable;