如何将具有相同列值的mysql行分组为一行? [英] How to group mysql rows with same column value into one row?

问题描述

我有两个表，关键字和数据.

I have two tables, keywords and data.

表关键字具有2列(id，关键字)，表数据具有3列(id [keywords.id的外键，名称，值).

Table keywords have 2 columns (id, keyword), table data have 3 columns (id[foreign key of keywords.id], name, value).

我正在使用此查询:

SELECT k.id, d.value, d.name
FROM keywords AS k
INNER JOIN data as d ON k.id = d.id

它返回如下内容:

1 123 name1
1 456 name2
2 943 name1
3 542 name1
3 532 name2
3 682 name3

每个id的值可以为0到3(将来可能会更多).

Each id can have values from 0 to 3 (maybe more in the future).

如何在同一行中检索具有相同ID的所有行?

How can I retrieve all the rows with the same id in the same row?

喜欢

1 123 456
2 943
3 542 532 682

我想这样做是因为我希望能够对值进行排序.

I want to do this because I want to be able to sort the values.

推荐答案

使用

Use GROUP_CONCAT() like this:

 SELECT k.id, GROUP_CONCAT(d.value)
  FROM keywords AS k
  INNER JOIN data as d ON k.id = d.id
  GROUP BY k.id

此外，您可能需要执行ORDER BY d.name来获取所需的确切值顺序.像这样:

Also, you may need to do ORDER BY d.name to get exact order of values as you want. Like this:

 SELECT k.id, GROUP_CONCAT(d.value ORDER BY d.name separator ' ')
  FROM keywords AS k
  INNER JOIN data as d ON k.id = d.id
  GROUP BY k.id

这篇关于如何将具有相同列值的mysql行分组为一行?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IT屋！