Question

I have a posts table structured this way:

id  |  title  |  content  |  tags

and a tags table

id  |  name  |  description

I put my tags in the posts table this way: 3,2,5,8 where the numbers are the tags table’s corresponding row number. Now what might me a good way to select related posts in my post by its tag(s)?

SELECT * FROM posts WHERE tags ? LIMIT 10

I’m quite bad at logic.

Answer 1

This is where database normalization comes in. Storing multiple tag ID’s in a single column is not a good idea. You should probably create a new table post_tags, with structure post_id | tag_id to link multiple tags to a single post.

You can then execute the following query:

SELECT * FROM posts
INNER JOIN post_tags ON post_tags.post_id = posts.id
WHERE post_tags.tag_id IN(id1,id2,etc.)