MySQL:将逗号分隔的列表拆分为多行

问题描述

我有一个非规范化表，其中一列包含逗号分隔的列表，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 |
+----------+-------------+   +--------------+-------+

我想将这些数据读入一个不提供程序语言的搜索引擎.

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

那么有没有办法要么在该列上建立连接或对该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 |
+---------+-------------+

如果 DBMS 支持返回表的函数，但 MySQL 显然不支持，我可以想到一个解决方案.

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 中可以这样实现

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车辆 ID 的长度，请使用以下查询

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      |
+---------+

更多信息请访问 http://amitbrothers.blogspot.in/2014/03/mysql-split-comma-separated-list-into.html

这篇关于MySQL:将逗号分隔的列表拆分为多行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！