匹配一行内的不同值 [英] Matching Different Value within One Row

问题描述

我想执行一个查询，借此我想检查 A 列上是否有某些值.A 可以只有 X 、 X 和 Y 或 X Y 和 Z 的组合.

I want to perform a query whereby I want to check whether on the columns A has either certain values. A could have only X , X and Y or a combination of X Y and Z.

为了更好地理解.我正在表中检查一本书的作者.该表具有 BOOK_ID 、 BOOK_TITLE 、 AUTHOR_NAME 和 AUTHOR_ORDER.

To give a better understanding. I am checking a book's author within a table itself. The table has the BOOK_ID , BOOK_TITLE , AUTHOR_NAME, AUTHOR_ORDER.

因此一本书可能有 1,2 或 3 个作者，按顺序在 AUTHOR_ORDER 行中列出.我非常努力地达到一个输出，如果一本书有 3 个作者，它将相应地从第一作者到第三作者显示.我现在被困在需要比较值并将其显示在输出中的部分.

So a book might have 1,2 or 3 authors, listed in order written inside the AUTHOR_ORDER row. I am trying very hard to reach an output where if a book has 3 authors, it will display accordingly from the first author to the third author. I am now stuck in the part where I need to compare the value and present it in the output.

知道如何在 MYSQL 输出中实现这一点吗?

Any idea how to achieve this in MYSQL output?

示例:

输出结果大致是这样的:

The output result is more or less like this:

如果标题的 au_ord 为 1,2 和 3，则应有一个新列，所有作者姓名都按升序排列.

If the title has au_ord of 1,2 and 3, there shall be a new column with all the authors name listed in ascending.

例如，对于标题 BU1032，作者行将是 Bennet, Green

推荐答案

我认为 GROUP_CONCAT 是您所追求的:

I think GROUP_CONCAT is what you are after:

SELECT  Title_ID, 
        Title,
        GROUP_CONCAT(au_LName ORDER BY au_Ord) AS Authors
FROM    Books
GROUP BY Title_ID, Title;

SQL FIDDLE

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