Question

I have a database that contains two tables:

• entries
• tags

The entries table contains posts that each have one or more tags. The problem is, each post can have any number of tags. In other words, I can’t have a ‘tag1’, ‘tag2’, etc. column and do a LEFT JOIN.

How should I set up entries so that each post can have any number of tags?

Answer 1

You need a mapping table.

Create a table called entries_tags that contains two columns: entry_id and tag_id, with a multi-key on both entries.

This is called a many-to-many relationship.