如何将逗号分隔的列转换为行并添加计数器

问题描述

我正在使用具有这些值的表

I am having a table with these values

表格:文档

id  |       document
----|-------------
1   |   doc.txt , doc1.txt , doc2.rtf , doc3.docx , doc4.doc
2   |   doc.txt 
3   |   doc.txt , doc1.txt 
4   |   doc.txt , doc1.txt , doc2.rtf 
5   |   doc.txt , doc1.txt , doc2.rtf , doc3.docx , doc4.doc
6   |   doc.txt , doc1.txt , doc2.rtf , doc3.docx 
7   |   doc.txt , doc1.txt , doc2.rtf , doc3.docx , doc4.doc
8   |   doc.txt , doc1.txt , doc2.rtf 
9   |   doc.txt , doc1.txt , doc2.rtf , doc3.docx , doc4.doc
10  |   doc.txt , doc1.txt 

SQL FIDDLE SCHEMA

我需要这样的结果. id = 5

I need result like this. Where id = 5

Counter |   docs
    ----|-----------
    1   |   doc.txt
    2   |   doc1.txt
    3   |   doc2.rtf
    4   |   doc3.docx
    5   |   doc4.doc

id = 4的地方

Counter |   docs
    ----|-----------
    1   |   doc.txt
    2   |   doc1.txt
    3   |   doc2.rtf

您看到我需要爆炸逗号分隔的列并计算其中有多少个值.我不喜欢这种模式，但是我正在处理一个现有项目，无法更改它.我需要计数器才能显示在用户界面中.因此，计数器也是必要的.我怎样才能做到这一点?同样，我无法在php端执行此操作，因为我使用的是pyrocms，并且我需要使用pyrocms tage显示它，这不允许我在视图中使用php.

You see i need to explode comma seperated column and count how many values are there. I dont like this schema but i am working on an existing project and can not change it. I need counter to display in the user interface. So counter is necessary too. How can i do that? Also i can not do it on the php end because i am using pyrocms and i need to display it using pyrocms tage which does not allow me to use php in the views.

推荐答案

查看此 SQL FIDDLE ，也许就是您想要的.您必须使用助手表sequence

Look at this SQL FIDDLE , maybe it is that you want. You must use helper table sequence

SELECT * FROM
(SELECT S.Id Counter,
REPLACE(SUBSTRING(SUBSTRING_INDEX(document, ' , ', S.Id),
       LENGTH(SUBSTRING_INDEX(document, ' , ', S.Id - 1)) + 1),
       ' , ', '') docs
FROM documents D, sequence S
WHERE D.id = 3) A
WHERE A.docs <> ''

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