blocks|key|4619901|text|透视在SQL中是静态的。你需要事先知道你想要输出的列，所以如果类别列表不是固定的，你就不能直接使用pivot。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4619902|如果您使用的是Microsoft+SQL+Server+(我知道您没有使用Microsoft+SQL+Server，但这只是为了举例)，那么您可以在存储过程中使用动态查询，如下所述：http://www.simple-talk.com/community/blogs/andras/archive/2007/09/14/37265.aspx|offset|length|4619903|现在，在MySql中，没有办法在SQL端执行动态SQL+(没有execute或sp_executeqsl的等价物)，因此您的最佳选择是在服务器端(aspnet服务器端)生成一个类似的sql查询。|4619904|另一个更简单的想法是忘记在SQL中做这件事，而是在你的C#代码中做聚合。|4619905|entityMap|0|LINK|mutability|MUTABLE|url|http://www.simple-talk.com/community/blogs/andras/archive/2007/09/14/37265.aspx^0|0|2J|27|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@$D|T|E|U|1|V]]|A|$]]|$1|F|3|G|5|6|7|W|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q]]]]

Pivot is static in SQL. You need to know in advance the columns you want in output, so if the list of categories is not fixed, you can't use pivot directly.

If you were using Microsoft SQL Server (which I know you're not, but it's for the sake of example), you could use a dynamic query in a stored procedure, as described here:
<a href="http://www.simple-talk.com/community/blogs/andras/archive/2007/09/14/37265.aspx" rel="nofollow">http://www.simple-talk.com/community/blogs/andras/archive/2007/09/14/37265.aspx</a>

Now, in MySql, there is no way to execute dynamic SQL on the sql side (no equivalent of EXECUTE or sp_executeqsl), so your best choice would be to generate a similar SQL query server-side (aspnet server-side).

Another simpler idea IMHO would be to forget about doing it in SQL, but to do the aggregation in your C# code.

blocks|key|4619850|text|您应该使用pivot|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|4619851|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikibooks.org/wiki/MySQL/Pivot_table^0|5|5|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

You should use <a href="http://en.wikibooks.org/wiki/MySQL/Pivot_table" rel="nofollow">pivot</a>

blocks|key|953238|text|要在SQL中做到这一点，您需要根据"Category“列中的可用值集动态生成查询。无论您是在纯SQL+(在存储过程中)还是在代码(动态SQL)中执行，这通常都是相当痛苦且容易出错的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|953239|我建议以存储的方式从数据库中读取值，然后动态创建一个DataTable或类似的结构作为UI的数据源。|953240|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

To do this in SQL, you'd need to dynamically generate your query based on the available set of values in the "Category" column. This is usually fairly painful and error prone, regardless of whether you do it in pure SQL (in a sproc) or in code (dynamic SQL).

I'd recommend reading your values from the database in the way that they are stored, then dynamically creating a DataTable or similar structure to use as the datasource for your UI.

blocks|key|4619964|text|我手头上没有MySql的工作版本，但由于脚本末尾的左连接，只要猫比狗多，它就可以工作。我忘记了MySql中没有完整的外部连接，但是您可以使用这个logic来尝试一下。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|4619965|但是这样做的要点是，如果您有两个具有任意键的表，您可以在键上进行连接，以获得您想要的结果。|4619966|--+drop+tables
+DROP+TABLE+dbo.cat
+DROP+TABLE+dbo.dog

+--create+dog+table
+create+table+dog+(
+dog_id+int+IDENTITY(1,1)+NOT+NULL
+,dog+varchar(50)
+)

+--add+dogs+only
+insert+into+dog+(dog)
+select+subcategory+
++FROM+play.dbo.test+
+where+category+=+'Dog'

+--create+cat+table
+create+table+cat+(
+cat_id+int+IDENTITY(1,1)+NOT+NULL
+,cat+varchar(50)
+)

+--add+cats+only
+insert+into+cat+(cat)
+select+subcategory+
++FROM+play.dbo.test+
+where+category+=+'cat'

+--+disply+everything
+SELECT+cat+
++++++,+dog
++from+dog+d
+--full+outer+join+cat+c
+left+join+dog+d
+on+d.dog_id+=+c.cat_id+|code-block|syntax|javascript|4619967|entityMap|0|LINK|mutability|MUTABLE|url|http://www.xaprb.com/blog/2006/05/26/how-to-write-full-outer-join-in-mysql/^0|20|5|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

I don't have a working version of MySql handy but this will work as long as there is always more cats than dogs because of the left join at the end of the script. I forgot that there isn't a full outer join in MySql but you could use this <a href="http://www.xaprb.com/blog/2006/05/26/how-to-write-full-outer-join-in-mysql/" rel="nofollow">logic</a> to try it out.

But the point of this is that if you have two tables with arbitrary keys you can join on the keys to get the results lined up like you want.

<pre><code>-- drop tables
 DROP TABLE dbo.cat
 DROP TABLE dbo.dog

 --create dog table
 create table dog (
 dog_id int IDENTITY(1,1) NOT NULL
 ,dog varchar(50)
 )

 --add dogs only
 insert into dog (dog)
 select subcategory 
 FROM play.dbo.test 
 where category = 'Dog'

 --create cat table
 create table cat (
 cat_id int IDENTITY(1,1) NOT NULL
 ,cat varchar(50)
 )

 --add cats only
 insert into cat (cat)
 select subcategory 
 FROM play.dbo.test 
 where category = 'cat'

 -- disply everything
 SELECT cat 
 , dog
 from dog d
 --full outer join cat c
 left join dog d
 on d.dog_id = c.cat_id 
</code></pre>

How do I turn this table:

+------------+-----------------+ 
| Category + Subcategory | 
+------------+-----------------+ 
|Cat..........+ Persian.........| 
|Cat..........+ Siamese........| 
|Cat..........+ Tabby...........| 
|Dog.........+ Poodle..........| 
|Dog.........+ Boxer............| 
+------------+----------------+

on it's side to get the following:

+------------+-----------------+ 
| Cat......... + Dog............. | 
+------------+-----------------+ 
+ Persian..+ Poodle.........+ 
+ Siamese + Boxer...........+ 
+ Burmese + ...................+ 
+------------+-----------------+ 

The initial table is from the following MySQL query:

<pre><code>select c.CATEGORYNAME, sc.NAME from subcategorydefinition sc
 join categorydefinition c on sc.CATEGORYID = c.CATEGORYID
 where c.ISDELETED = 0
 order by CATEGORYNAME, NAME ASC
</code></pre>

And I want to display it in (probably) a Gridview. 

Cheers!

Turning a table "on it's side" in asp.net - how?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我该如何翻转这张桌子：+类别+子类别+|Cat..........+波斯语.........||Cat..........+暹罗语....||Cat..........+猫...........||Dog.........+ Poodle..........||Dog.........+ Boxer............|+在它的一侧，获取以下内容：+|猫.........+狗.........

问在asp.net中把桌子“倒过来”--如何？
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