Sql 动态SELECT语句，根据当前值和未来值生成列

目前正在SQL Server 2008中生成一个

SELECT

语句，但希望使该

SELECT

语句成为动态的，因此可以根据表中的值定义列。我听说过透视表和游标，但在我目前的水平上似乎有点难以理解，下面是代码

DECLARE @date DATE = null

IF @date is null
set @ date = GETDATE() as DATE

SELECT
    Name,
    value1,
    value2,
    value3,
    value4
FROM ref_Table a
FULL OUTER JOIN (
    SELECT
       PK_ID ID,
       sum(case when FK_ContainerType_ID = 1 then 1 else null) Box,
       sum(case when FK_ContainerType_ID = 2 then 1 else null) Pallet,
       sum(case when FK_ContainerType_ID = 3 then 1 else null) Bag,
       sum(case when FK_ContainerType_ID = 4 then 1 else null) Drum
    from 
       Packages  
    WHERE 
       @date between PackageStart AND PackageEnd
    group by PK_ID ) b on a.Name = b.ID
where 
    Group = 0

下面的内容对我来说非常有用，但是PK_Type_ID和列的名称（PackageNameX，…）是硬编码的，我需要动态的，它可以基于

Package

表中的当前值或未来值构建自身

如果您能在正确的方向上提供任何帮助或指导，我们将不胜感激

应要求

ref\u表

（主键ID，名称）

包装

（主键标识、FK\u参考表标识、FK\u集装箱类型标识、包装开始日期、包装结束日期）

容器类型

（主键ID，类型）

结果应该是这样的

Name     Box     Pallet    Bag    Drum
---------------------------------------
John                                1
Mary                        1
Albert              1
Jane       1

---

正如我所说，下面的代码非常有效，问题是

容器

表将增长，我需要复制相同的报告，而无需对列进行硬编码。

您需要构建的称为动态透视。若你们搜索那个术语，在堆栈上有很多很好的参考文献

以下是您的场景的解决方案：

IF OBJECT_ID('tempdb..##ref_Table') IS NOT NULL
    DROP TABLE ##ref_Table
IF OBJECT_ID('tempdb..##Packages') IS NOT NULL
    DROP TABLE ##Packages
IF OBJECT_ID('tempdb..##ContainerType') IS NOT NULL
    DROP TABLE ##ContainerType

SET NOCOUNT ON

CREATE TABLE ##ref_Table (PK_ID INT, NAME NVARCHAR(50))
CREATE TABLE ##Packages (PK_ID INT, FK_ref_Table_ID INT, FK_ContainerType_ID INT, PackageStartDate DATE, PackageEndDate DATE)
CREATE TABLE ##ContainerType (PK_ID INT, [Type] NVARCHAR(50))

INSERT INTO ##ref_Table (PK_ID,NAME)
SELECT 1,'John' UNION
SELECT 2,'Mary' UNION
SELECT 3,'Albert' UNION
SELECT 4,'Jane'

INSERT INTO ##Packages (PK_ID, FK_ref_Table_ID, FK_ContainerType_ID, PackageStartDate, PackageEndDate)
SELECT 1,1,4,'2014-01-01','2014-01-30' UNION
SELECT 2,2,3,'2014-01-01','2014-01-30' UNION
SELECT 3,3,2,'2014-01-01','2014-01-30' UNION
SELECT 4,4,1,'2014-01-01','2014-01-30' 

INSERT INTO ##ContainerType (PK_ID, [Type])
SELECT 1,'Box' UNION
SELECT 2,'Pallet' UNION
SELECT 3,'Bag' UNION
SELECT 4,'Drum' 

DECLARE @DATE DATE, @PARAMDEF NVARCHAR(MAX), @COLS NVARCHAR(MAX), @SQL NVARCHAR(MAX)
SET @DATE = '2014-01-15'

SET @COLS = STUFF((SELECT DISTINCT  ',' + QUOTENAME(T.[Type])
            FROM ##ContainerType T
            FOR XML PATH, TYPE).value('.', 'NVARCHAR(MAX)'),1,1,'')

SET @SQL = 'SELECT [Name], ' + @COLS + ' 
            FROM (SELECT [Name], [Type], 1 AS Value
                  FROM ##ref_Table R
                  JOIN ##Packages P ON R.PK_ID = P.FK_ref_Table_ID
                  JOIN ##ContainerType T ON P.FK_ContainerType_ID = T.PK_ID
                  WHERE @DATE BETWEEN P.PackageStartDate AND P.PackageEndDate) X
            PIVOT (COUNT(Value) FOR [Type] IN (' + @COLS + ')) P
            '
PRINT @COLS
PRINT @SQL
SET @PARAMDEF = '@DATE DATE'
EXEC SP_EXECUTESQL @SQL, @PARAMDEF, @DATE=@DATE

输出：

Name    Bag     Box     Drum    Pallet
Albert  0       0       0       1
Jane    0       1       0       0
John    0       0       1       0
Mary    1       0       0       0

---

静态查询：

SELECT [Name],[Box],[Pallet],[Bag],[Drum] FROM
(
    SELECT *
    FROM
    (
        SELECT  rf.Name,cnt.[Type], pk.PK_ID AS PKID, rf.PK_ID AS RFID
        FROM ref_Table rf INNER JOIN Packages pk ON rf.PK_ID = pk.FK_ref_Table_ID
        INNER JOIN ContanerType cnt ON cnt.PK_ID = pk.FK_ContainerType_ID
     ) AS SourceTable
    PIVOT
    (
           COUNT(PKID )
           FOR [Type]
           IN ( [Box],[Pallet],[Bag],[Drum])
    ) AS PivotTable
) AS Main
ORDER BY RFID

DECLARE @columnList nvarchar (MAX)
DECLARE @pivotsql nvarchar (MAX)

SELECT @columnList =   STUFF(
             (
             SELECT ',' + '[' + [Type] + ']'
           FROM ContanerType
           FOR XML PATH( '')
           )
        ,1, 1,'' )


SET @pivotsql =
N'SELECT [Name],' + @columnList + ' FROM
(
    SELECT *
    FROM
    (
        SELECT  rf.Name,cnt.[Type], pk.PK_ID AS PKID, rf.PK_ID AS RFID
        FROM ref_Table rf INNER JOIN Packages pk ON rf.PK_ID = pk.FK_ref_Table_ID
        INNER JOIN ContanerType cnt ON cnt.PK_ID = pk.FK_ContainerType_ID
     ) AS SourceTable
    PIVOT
    (
           COUNT(PKID )
           FOR [Type]
           IN ( ' + @columnList + ')
    ) AS PivotTable
) AS Main
ORDER BY RFID;'

EXEC sp_executesql @pivotsql

动态查询：

SELECT [Name],[Box],[Pallet],[Bag],[Drum] FROM
(
    SELECT *
    FROM
    (
        SELECT  rf.Name,cnt.[Type], pk.PK_ID AS PKID, rf.PK_ID AS RFID
        FROM ref_Table rf INNER JOIN Packages pk ON rf.PK_ID = pk.FK_ref_Table_ID
        INNER JOIN ContanerType cnt ON cnt.PK_ID = pk.FK_ContainerType_ID
     ) AS SourceTable
    PIVOT
    (
           COUNT(PKID )
           FOR [Type]
           IN ( [Box],[Pallet],[Bag],[Drum])
    ) AS PivotTable
) AS Main
ORDER BY RFID

DECLARE @columnList nvarchar (MAX)
DECLARE @pivotsql nvarchar (MAX)

SELECT @columnList =   STUFF(
             (
             SELECT ',' + '[' + [Type] + ']'
           FROM ContanerType
           FOR XML PATH( '')
           )
        ,1, 1,'' )


SET @pivotsql =
N'SELECT [Name],' + @columnList + ' FROM
(
    SELECT *
    FROM
    (
        SELECT  rf.Name,cnt.[Type], pk.PK_ID AS PKID, rf.PK_ID AS RFID
        FROM ref_Table rf INNER JOIN Packages pk ON rf.PK_ID = pk.FK_ref_Table_ID
        INNER JOIN ContanerType cnt ON cnt.PK_ID = pk.FK_ContainerType_ID
     ) AS SourceTable
    PIVOT
    (
           COUNT(PKID )
           FOR [Type]
           IN ( ' + @columnList + ')
    ) AS PivotTable
) AS Main
ORDER BY RFID;'

EXEC sp_executesql @pivotsql

下面的教程将帮助您了解PIVOT功能：

我们编写sql查询是为了从数据库表中获得不同的结果集，如完整、部分、计算、分组、排序等。然而，有时我们需要轮换桌子。听起来很困惑

让我们保持简单，考虑下面两个屏幕抓取。

SQL表：

预期结果：

哇，看起来工作量很大！这是复杂的sql、临时表、循环、聚合……等等的组合

别担心，让我们保持简单，愚蠢（亲吻）

MS SQL Server 2005及更高版本有一个名为PIVOT的函数。它使用非常简单，功能强大。借助此函数，我们将能够旋转sql表和结果集

实现这一目标的简单步骤：

SELECT [Name],[Box],[Pallet],[Bag],[Drum] FROM
(
    SELECT *
    FROM
    (
        SELECT  rf.Name,cnt.[Type], pk.PK_ID AS PKID, rf.PK_ID AS RFID
        FROM ref_Table rf INNER JOIN Packages pk ON rf.PK_ID = pk.FK_ref_Table_ID
        INNER JOIN ContanerType cnt ON cnt.PK_ID = pk.FK_ContainerType_ID
     ) AS SourceTable
    PIVOT
    (
           COUNT(PKID )
           FOR [Type]
           IN ( [Box],[Pallet],[Bag],[Drum])
    ) AS PivotTable
) AS Main
ORDER BY RFID

DECLARE @columnList nvarchar (MAX)
DECLARE @pivotsql nvarchar (MAX)

SELECT @columnList =   STUFF(
             (
             SELECT ',' + '[' + [Type] + ']'
           FROM ContanerType
           FOR XML PATH( '')
           )
        ,1, 1,'' )


SET @pivotsql =
N'SELECT [Name],' + @columnList + ' FROM
(
    SELECT *
    FROM
    (
        SELECT  rf.Name,cnt.[Type], pk.PK_ID AS PKID, rf.PK_ID AS RFID
        FROM ref_Table rf INNER JOIN Packages pk ON rf.PK_ID = pk.FK_ref_Table_ID
        INNER JOIN ContanerType cnt ON cnt.PK_ID = pk.FK_ContainerType_ID
     ) AS SourceTable
    PIVOT
    (
           COUNT(PKID )
           FOR [Type]
           IN ( ' + @columnList + ')
    ) AS PivotTable
) AS Main
ORDER BY RFID;'

EXEC sp_executesql @pivotsql

确定将成为所需结果集一部分的所有列

查找我们将应用聚合的列（总和、平均值、最大值、最小值等）

确定将哪些值作为列标题的列

指定步骤3中提到的列值，用逗号分隔并用方括号括起来

因此，如果我们现在按照上述四个步骤，从上述销售表中提取信息，将如下所示：

年、月、销售额

销售额

月

【一月】、【二月】、【三月】。。。。等

如果到目前为止，以上所有步骤对您都有意义，那么我们就快到了

现在我们有了我们需要的所有信息。我们现在要做的就是在下面的模板中填写所需信息。 模板： 我们的SQL查询应该如下所示：

挑选*

FROM
(
    SELECT SalesYear, SalesMonth,Amount
    FROM Sales
 ) AS SourceTable
PIVOT
(
       SUM(Amount )
       FOR SalesMonth
       IN ( [Jan],[Feb] ,[Mar],
            [Apr],[May],[Jun] ,[Jul],
            [Aug],[Sep] ,[Oct],[Nov] ,[Dec])
) AS PivotTable;

在上面的查询中，我们硬编码了列名。当你必须指定许多列的时候，这并不有趣

然而，有一项工作如下：

DECLARE @columnList nvarchar (MAX)
DECLARE @pivotsql nvarchar (MAX)

SELECT @columnList =   STUFF(
             (
               SELECT ',' + '[' + SalesMonth + ']'
               FROM Sales
               GROUP BY SalesMonth
               FOR XML PATH( '')
           )
        ,1, 1,'' )

SET @pivotsql =
       N'SELECT *
      FROM
      (
            SELECT SalesYear, SalesMonth,Amount
            FROM Sales
       ) AS SourceTable
      PIVOT
      (
           SUM(Amount )
           FOR SalesMonth
           IN ( ' + @columnList +' )
      ) AS PivotTable;'

EXEC sp_executesql @pivotsql

希望本教程能对某些人有所帮助。

---

喜欢编码。

您能提供一个包含一些示例数据和预期输出示例的模式吗？注意：如果您希望看到

NULL

而不是0表示缺少的数据，请将动态SQL字符串中的

COUNT（Value）

更改为

SUM（Value）

。