我有以下表格:
news
idNews | title
1 | Title 1
2 | Title 2
3 | Title 3
4 | Title 4
tags
idTag | name
1 | Name_tag1
2 | Name_tag2
3 | Name_tag3
4 | Name_tag4
Run Code Online (Sandbox Code Playgroud)
MappingTable:
tag_news
idTag | idNews
1 | 1
2 | 1
1 | 2
2 | 2
2 | 3
3 | 3
4 | 3
4 | 4
Run Code Online (Sandbox Code Playgroud)
我想通过给一个idNews来获取几乎有一个共同标签的相关新闻的标题.我能用三个SELECT做到这一点:
SELECT title FROM news WHERE idNews IN
(SELECT DISTINCT idNews FROM tag_news
WHERE …Run Code Online (Sandbox Code Playgroud)