select relevance title based on tag similar to like with mysql

问题

TAGS

tag_id   post_id   value
------------------------
1        1         some
2        1         good
3        1         title
4        2         some
5        2         good
6        3         some
7        4         good
8        4         title

POSTS

post_id  title
-------------------
1        some good title
2        some good
3        some
4        good title

how can we get the post_id = 1 and 2 that contains value some and good in the same post_id?

so the result is

RESULT
title
----------
some good title
some good

good title dosent show becouse there is no some value in post_id = 4 in tags. some doesnt show beouse the requirement good

回答1:

Try LIKE multiple time:

SELECT * FROM post
WHERE title LIKE '%some%'
AND title LIKE '%good%'

See this SQLFiddle

You can also join both tables like this:

SELECT post.post_id, title FROM Post
RIGHT JOIN Tags
ON post.post_id = tags.post_id
WHERE Tags.value IN ('some','good')
GROUP BY post.Post_ID
HAVING COUNT(*)>1;