MySQL:将逗号分隔的列表分成多行 [英] MySQL: Split comma separated list into multiple rows

问题描述

我有一个未规范化的表，该表的列包含一个用逗号分隔的列表，该列表是另一个表的外键:

I have an unnormalized table with a column containing a comma separated list that is a foreign key to another table:

+----------+-------------+   +--------------+-------+
| part_id  | material    |   | material_id  | name  |
+----------+-------------+   +--------------+-------+
|      339 | 1.2mm;1.6mm |   |            1 | 1.2mm |
|      970 | 1.6mm       |   |            2 | 1.6mm |
+----------+-------------+   +--------------+-------+

我想将此数据读入不提供程序语言的搜索引擎中.

I want to read this data into a search engine that offers no procedural language.

因此，有没有办法 对此列进行连接或对此数据运行查询，以将适当的条目插入到新表中? 结果数据应如下所示:

So is there a way to either make a join on this column or run a query on this data that inserts appropriate entries into a new table? The resulting data should look like this:

+---------+-------------+
| part_id | material_id |
+---------+-------------+
|     339 |           1 |
|     339 |           2 |
|     970 |           2 |
+---------+-------------+

我想出了一个解决方案，如果DBMS支持的函数返回一个表，但是MySQL显然没有.

I could think of a solution if the DBMS supported functions returning a table but MySQL apparently doesn't.

推荐答案

在MySQL中，可以通过以下方式实现

In MySQL this can be achieved as below

SELECT id, length FROM vehicles WHERE id IN ( 117, 148, 126) 

+---------------+
| id  | length  |
+---------------+
| 117 | 25      |
| 126 | 8       |
| 148 | 10      |
+---------------+

SELECT id,vehicle_ids FROM load_plan_configs WHERE load_plan_configs.id =42

+---------------------+
| id  | vehicle_ids   |
+---------------------+
| 42  | 117, 148, 126 |
+---------------------+

现在要获取逗号分隔的vehicle_ids的长度，请在下面的查询中使用

Now to get the length of comma separated vehicle_ids use below query

Output

SELECT length 
FROM   vehicles, load_plan_configs   
WHERE  load_plan_configs.id = 42 AND FIND_IN_SET(
       vehicles.id, load_plan_configs.vehicle_ids
)

+---------+
| length  |
+---------+
| 25      |
| 8       |
| 10      |
+---------+

有关详细信息，请访问http://amitbrothers.blogspot.in/2014/03/mysql-split-comma-separated-list-into.html

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