在用特殊字符分隔的表中拆分列值

问题描述

我有一个看起来像这样的表：

Table 1

+----+--------+----------+
| ID | Name   |   SIZE   |      
+----+--------+----------+
| 1  | Style1 | S,M,L,XL |  
+----+--------+----------+

我需要遍历整个表并将其加载到另一个如下所示的表中，而无需使用SPLIT_STRING，而我们正在使用没有该功能的sql Server 2012。

我还知道将插入到新表中的最大值将为100列宽。我对sql还是很陌生，对功能以及如何使用它们不太满意。

Table 2

+----+--------+-------+-------+-------+-------+-----+-------+
| ID |  NAME  | SIZE1 | SIZE2 | SIZE3 | SIZE4 | ... | SIZEN |
+----+--------+-------+-------+-------+-------+-----+-------+
|  1 | Style1 | S     | M     | L     | XL    |     |       |
+----+--------+-------+-------+-------+-------+-----+-------+

谢谢

解决方法

由于您对Sql Server 2012感到困惑，因此可以使用一些XML语法。

这是应该帮助您的代码示例：

DECLARE @mockup TABLE (
    [id] INT,[Name] VARCHAR(max),[Size] VARCHAR(max)
    );

INSERT INTO @mockup
VALUES (
    1,'Style','S,M,L,XL'
    )

;WITH Splitted
AS (
    SELECT [id],[Name],[Size],CAST('<x>' + REPLACE([Size],','</x><x>') + '</x>' AS XML) AS Parts
    FROM @mockup
    )
SELECT [id],Parts.value(N'/x[1]','varchar(5)') AS Column_1,Parts.value(N'/x[2]','varchar(5)') AS Column_2,Parts.value(N'/x[3]','varchar(5)') AS Column_3,Parts.value(N'/x[4]','varchar(5)') AS Column_4,Parts.value(N'/x[5]','varchar(5)') AS Column_5,Parts.value(N'/x[6]','varchar(5)') AS Column_6
    --and so on until column 100
FROM Splitted;

结果：

基本上，以上代码将Size列的内容转换为xml片段：

<x>S</x><x>M</x><x>L</x><x>XL</x>
    

然后，您可以使用value() xml方法（更多信息here）提取不同列中的每个值。

,

最简单的方法是动态SQL，尤其是在大小列数变化的情况下。这是我放在一起可以在SSMS中运行的示例。它采用了@Andrea提到的某些相同原理并对其进行了扩展。

SET NOCOUNT ON;

DECLARE @Sizes TABLE ( Id INT,Name VARCHAR(50),Sizes VARCHAR(50) );
INSERT INTO @Sizes ( Id,Name,Sizes ) VALUES
    ( 1,'Style1',XL');

DECLARE @dynamic_sql VARCHAR(MAX);
SELECT @dynamic_sql = 'SELECT '
    +  CAST ( [Id] AS VARCHAR(10) ) + ' AS [ID],'
    + '''' + [Name] + ''' AS [NAME],'
    + List.Cols + ';'
FROM @Sizes
OUTER APPLY ( 
    SELECT CAST ( '<sizes><size>' + REPLACE ( Sizes,'</size><size>' ) + '</size></sizes>' AS XML ) SizeXml
) AS x
OUTER APPLY (

    SELECT STUFF ( (

        SELECT
            ',''' + Size + ''' AS [SIZE' + CAST ( SizeId AS VARCHAR(10) ) + ']' AS "text()"
        FROM (

            SELECT
                ROW_NUMBER() OVER ( ORDER BY ( SELECT NULL ) ) AS SizeId,n.s.value ( '.','VARCHAR(50)' ) AS Size 
            FROM x.SizeXml.nodes('//sizes/size') n ( s )

        ) AS xml_list FOR XML PATH ('')

    ),1,2,'' ) AS Cols

) AS List
WHERE Id = 1;

-- Execute the dynamic SQL statement.
EXEC ( @dynamic_sql );

返回

+----+--------+-------+-------+-------+-------+
| ID |  NAME  | SIZE1 | SIZE2 | SIZE3 | SIZE4 |
+----+--------+-------+-------+-------+-------+
|  1 | Style1 | S     | M     | L     | XL    |
+----+--------+-------+-------+-------+-------+