Question

I recently thought that storing an array in MySQL database would solve my problems… then I went and banged my head on a wall until I realised that there was an easier solution to my problem. Unfortunately I can’t seem to figure out what the hell I need to do.

I have two tables. User and Entry. Each user can be the Author of any number of entries. One to many right? Well the problem comes from the fact that each entry can have many users. -_-;

As you can imagine, doing this using arrays would be…not only cumbersome but also stupid, especially if someone managed to accumulate 2000 entries. I had anticipated that I might need to create an extra table and some resources do seem to suggest it but the resources aren’t as clear as I would have hoped. I will need to get all the users for a post and somewhere else, I’ll need to get all the posts for a user.

Can someone explain the best way of doing this? (Without using arrays of course =p)

Answer 1

you need to make 3 tables:

• user (primary key = id)
  • id
  • name
  • …
• entry (primary key = id)
  • id
  • text
  • …
• userentry (primary key = complex key user,entry)
  • user
  • entry

if you want to get an entrys users, just do

SELECT
  user.*
FROM
  userentry
INNER JOIN
  user
ON
  userentry.user = user.id
WHERE
  userentry.entry = [your entry-id]

and to get all entrys of a user, just do it the other way around:

SELECT
  entry.*
FROM
  userentry
INNER JOIN
  entry
ON
  userentry.entry = entry.id
WHERE
  userentry.user = [your user-id]