数据透视表问题:原始表或枚举中没有标识符 [英] Pivot Table issue: no identifier in original table or enumeration

问题描述

我在使用数据透视表或动态表时遇到问题.

I'm having an issue with using pivot or dynamic tables.

我发现这个例子对理解我如何完成这项任务非常有帮助.但是，我缺少内部标识符列.

I found this example to be very helpful in understanding how I can accomplish this task; however, I am missing the inside identifier column.

SQL Server中的动态数据透视列

上面的帖子中提供了一个SQL提琴: http://www .sqlfiddle.com/#！3/7fad2/6

There is an SQL fiddle provided here in the post above: http://www.sqlfiddle.com/#!3/7fad2/6

您可以看到在第二个表propertyObjects中，每个objectID都有一个计数1、2、3、4.我没有那个propertyID计数.这就是我所有的

You can see that in the second table propertyObjects, there is a count 1, 2, 3, 4 for each objectID. I do not have that propertyID count. This is all I have

case  category
1      xx
1      xyx
1      abc
2      ghj
2      asdf
3      dfgh

如您所见，每种情况下我都有许多不同的类别，但是没有类别标识符字段.

As you can see I have a number of different categories for each case, but no category identifier field.

这就是我需要的:

case  cat1  cat2  cat3
1     xx    xyx   abc
2     ghj   asdf
3     dfgh

所以我想我可能需要在源表中添加一列，并以某种方式枚举每种情况下的类别.这将使我可以在提供的示例中使用枢轴.有什么想法吗?

So I am thinking I might need to add a column to the source table and somehow enumerate the categories per case. This would make it possible for me to use the pivot in the provided example. Thoughts?

我尝试使用row_number来完成此操作，但它不会在每种情况下都停止，它只是继续对整个表进行计数.

I tried to use row_number to accomplish this, but it does not stop at each case number, it just continues on counting the entire table.

推荐答案

由于每个case具有多个值，因此您将需要使用row_number()获取每个类别的单独列.

Since you have multiple values for each case, then you will need to use row_number() to get the separate columns for each category.

在编写动态SQL版本之前，我将首先编写一个硬编码版本.该代码将类似于:

Before you write the dynamic SQL version I would first write a hard-coded version. The code will be similar to:

SELECT [case], cat1, cat2, cat3
FROM
(
    SELECT [case], category,
      'cat'+
        cast(row_number() over(partition by [case] 
                               order by category) as varchar(10)) seq
    FROM yourTable
) x
PIVOT
(
   max(category)
   for seq in (cat1, cat2, cat3)
)p;

请参见带演示的SQL提琴.

现在您有了逻辑，然后可以将其转换为动态SQL:

Now you have the logic down, then you can convert it to dynamic SQL:

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT distinct ',' + QUOTENAME('cat'+cast(seq as varchar(10))) 
                    from
                    (
                      select row_number() over(partition by [case] 
                                               order by category) seq
                      from yourtable
                    ) d
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT [case],' + @cols + ' 
            from 
            (
              SELECT [case], category,
                ''cat''+
                  cast(row_number() over(partition by [case] 
                                         order by category) as varchar(10)) seq
              FROM yourTable
            ) x
            pivot 
            (
                max(category)
                for seq in (' + @cols + ')
            ) p '

execute sp_executesql @query;

请参见带演示的SQL小提琴.这将为您提供结果:

See SQL Fiddle with Demo. This will give you the result:

| CASE | CAT1 |   CAT2 |   CAT3 |
|------|------|--------|--------|
|    1 |  abc |     xx |    xyx |
|    2 | asdf |    ghj | (null) |
|    3 | dfgh | (null) | (null) |

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