Question

I have 4 MySQL tables

folder, folder_users, folder_posts, posts

I need to build a view which queries the above and returns data which I can the filter based on a user id

folder has:

id, userid, title, date

folder_users has:

id, folderid, userid

folder_posts has:

id, folderid, postid

posts has:

id, userid, media, text, type

The aim is to display a set of folders to a logged in user where they have access to the folder and that shows the latest image (held in media column on posts table) ideally I would like to get this into a MySQL View and have it ordered by folder.date

I am struggling as where to start with this query so any help would be really great thanks.

* EDIT just thought of a missing element **

The posts table will have other type of posts that will mean that some posts in a folder may have no media, so the query needs to compensate for this i.e. where there is media make sure that this included in the result and where no media then don’t

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Answer 1

SELECT
  p.media, f.title
FROM
  posts p
INNER JOIN
  folder_posts fp
  ON
  fp.postid=p.id
INNER JOIN
  folder_users fu
  ON
  fu.id=fp.folderid
INNER JOIN
  folder f
  ON 
  f.id=fu.folderid AND f.userid='LOGED_USER_ID'
WHERE p.media IS NOT NULL
GROUP BY p.id
ORDER BY f.date