sql-server - 根据条件消除 XML 中的行

Question

这是创建所需数据的脚本:

CREATE TABLE [dbo].[TestXML](
[ID] [int] NOT NULL,
[PID] [int] NULL,
[Code] [int] NULL,
[Col1] [int] NULL,
[Col2] [int] NULL,
[Col3] [decimal](6, 2) NULL,
[Col4] [decimal](6, 2) NULL,
[Col5] [int] NULL,
CONSTRAINT [PK_TestXML] PRIMARY KEY CLUSTERED ([ID] ASC)
)

GO

CREATE TABLE [dbo].[XML_Columns_Reference](
[TableName] nvarchar(10) NULL,
[TableNameXML] nvarchar(10) NULL,
[ColumnName] nvarchar(10) NULL,
[ColumnNameXML] nvarchar(10) NULL,
[ColumnOrder] [int] NULL,
[GroupName] nvarchar(10) NULL,
[GroupOrder] [int] NULL,
[Category] [int] NULL
) ON [PRIMARY]

CREATE TABLE [dbo].[XML_NoUseCols_Ref](
[TableNameXML] nvarchar(10) NULL,
[Code] [int] NULL,
[ColumnName] nvarchar(10) NULL
) ON [PRIMARY]

GO

INSERT [dbo].[TestXML] ([ID], [PID], [Code], [Col1], [Col2], [Col3], [Col4], [Col5]) VALUES (1, 1000, 10, 1, 2, CAST(0.20 AS Decimal(6, 2)), CAST(0.10 AS Decimal(6, 2)), 1)
INSERT [dbo].[TestXML] ([ID], [PID], [Code], [Col1], [Col2], [Col3], [Col4], [Col5]) VALUES (2, 1000, 20, NULL, 1, CAST(1.00 AS Decimal(6, 2)), CAST(1.00 AS Decimal(6, 2)), 1)
INSERT [dbo].[TestXML] ([ID], [PID], [Code], [Col1], [Col2], [Col3], [Col4], [Col5]) VALUES (3, 1000, 30, NULL, NULL, CAST(2.00 AS Decimal(6, 2)), CAST(2.00 AS Decimal(6, 2)), 5)

INSERT [dbo].[XML_Columns_Reference] ([TableName], [TableNameXML], [ColumnName], [ColumnNameXML], [ColumnOrder], [GroupName], [GroupOrder], [Category]) VALUES (N'TestXML', N'T', N'Col1', N'N', 1, N'A', 2, NULL)
INSERT [dbo].[XML_Columns_Reference] ([TableName], [TableNameXML], [ColumnName], [ColumnNameXML], [ColumnOrder], [GroupName], [GroupOrder], [Category]) VALUES (N'TestXML', N'T', N'Col2', N'V', 2, N'A', 2, NULL)
INSERT [dbo].[XML_Columns_Reference] ([TableName], [TableNameXML], [ColumnName], [ColumnNameXML], [ColumnOrder], [GroupName], [GroupOrder], [Category]) VALUES (N'TestXML', N'T', N'Col3', N'N', 1, N'B', 3, NULL)
INSERT [dbo].[XML_Columns_Reference] ([TableName], [TableNameXML], [ColumnName], [ColumnNameXML], [ColumnOrder], [GroupName], [GroupOrder], [Category]) VALUES (N'TestXML', N'T', N'Col4', N'V', 2, N'B', 3, NULL)
INSERT [dbo].[XML_Columns_Reference] ([TableName], [TableNameXML], [ColumnName], [ColumnNameXML], [ColumnOrder], [GroupName], [GroupOrder], [Category]) VALUES (N'TestXML', N'T', N'Col5', N'A', 1, N'C', 1, NULL)

INSERT [dbo].[XML_NoUseCols_Ref] ([TableNameXML], [Code], [ColumnName]) VALUES (N'T', 20, N'Col1')
INSERT [dbo].[XML_NoUseCols_Ref] ([TableNameXML], [Code], [ColumnName]) VALUES (N'T', 30, N'Col1')
INSERT [dbo].[XML_NoUseCols_Ref] ([TableNameXML], [Code], [ColumnName]) VALUES (N'T', 30, N'Col2')

这是我运行的查询:

DECLARE @PID int
SET @PID=1000
SELECT
GroupName as [@n],
(SELECT
Code [@n],
(SELECT
ColumnNameXML as [col/@n],
CASE name
WHEN 'Col1' THEN ISNULL(Col1,0)
WHEN 'Col2' THEN ISNULL(Col2,0)
WHEN 'Col3' THEN ISNULL(Col3,0)
WHEN 'Col4' THEN ISNULL(Col4,0)
WHEN 'Col5' THEN ISNULL(Col5,0)
END AS [col/col_value]
FROM sys.columns
CROSS JOIN TestXML ls1
INNER JOIN XML_Columns_Reference r1
ON sys.columns.name=r1.columnname   
WHERE object_id = OBJECT_ID('TestXML') and r1.TableNameXML='T'
and ls1.PID=@PID and ls1.ID=ls2.ID and r1.GroupName=r2.GroupName    
and r1.ColumnName NOT IN (SELECT [ColumnName] 
FROM XML_NoUseCols_Ref  
WHERE TableNameXML='T' and [Code]=ls1.Code
GROUP BY ColumnName)
ORDER BY column_id
FOR XML PATH(''),TYPE
)
FROM TestXML ls2
WHERE ls2.PID=@PID  
FOR XML PATH('cat'),TYPE
)
FROM sys.columns
CROSS JOIN TestXML ls3
INNER JOIN XML_Columns_Reference r2
ON sys.columns.name=r2.columnname
WHERE object_id = OBJECT_ID('TestXML') and ls3.PID=@PID and r2.TableNameXML='T'
GROUP BY GroupName
ORDER BY MIN(groupOrder)
FOR XML PATH('grp'),TYPE

结果:

我需要的是当 XML_NoUseCols_Ref 中有一个组中所有行的引用(您可以在 XML_Columns_Reference 中获取组)以消除 XML 中的 cat 行。 在示例中， grp n="A"中的 cat n="30"

任何形式的帮助将不胜感激。 谢谢。

Answer 1

我建议不要在很多地方重复这个逻辑，而是使用 CTE(类似于临时 View )来预取数据。其余部分是相当简单的嵌套与相关子查询，并且更好读:

希望我正确理解了你的逻辑......

WITH cte AS
(       
        SELECT ls1.ID,ls1.PID,ls1.Code
              ,r1.ColumnNameXML,r1.GroupName,r1.GroupOrder
              ,CASE name
                WHEN 'Col1' THEN ISNULL(Col1,0)
                WHEN 'Col2' THEN ISNULL(Col2,0)
                WHEN 'Col3' THEN ISNULL(Col3,0)
                WHEN 'Col4' THEN ISNULL(Col4,0)
                WHEN 'Col5' THEN ISNULL(Col5,0)
                END AS ColumnValue
        FROM sys.columns
        CROSS JOIN TestXML ls1
        INNER JOIN XML_Columns_Reference r1
        ON sys.columns.name=r1.columnname   
        WHERE object_id = OBJECT_ID('TestXML') and r1.TableNameXML='T'
        and ls1.PID=@PID  
        and r1.ColumnName NOT IN (  SELECT [ColumnName] 
                                    FROM XML_NoUseCols_Ref  
                                    WHERE TableNameXML='T' and [Code]=ls1.Code
                                    GROUP BY ColumnName)
) 
SELECT GroupName AS [@n]
      ,(
        SELECT Code AS [@n]
              ,(
                SELECT cte3.ColumnNameXML AS [@n]
                      ,cte3.ColumnValue AS [col_value]
                FROM cte cte3
                WHERE cte3.GroupName=cte1.GroupName AND cte3.Code=cte2.Code
                ORDER BY cte3.ColumnNameXML
                FOR XML PATH('col'),TYPE
               )
        FROM cte cte2
        WHERE cte1.GroupName=cte2.GroupName
        GROUP BY cte2.Code
        ORDER BY cte2.Code
        FOR XML PATH('cat'),TYPE
       )
FROM cte cte1
GROUP BY GroupName,GroupOrder
ORDER BY GroupOrder
FOR XML PATH('grp');