Question

I have two tables. The first table holds simple user data and has the columns

$username, $text, $image 

(this is called “USERDATA”).

The second table holds information about which users “follow” other users, which is set up with the columns

$username and $usertheyfollow 

(this is called “FOLLOWS”).

What I need to do is display the data individually to each user so that it is relevant to them. This means that userABC for instance, needs to be able to view the $text and $image inputs for all of the users whom he/she follows. To do this, I believe I need to write a sql query that involves first checking who the logged in user is (in this case userABC), then selecting all instances of $usertheyfollow on table FOLLOWS that has the corresponding value of "userABC." I then need to go back to my USERDATA table and select $text and $image that has a corresponding value of $usertheyfollow. Then I can just display this using echo command or the like…

How would I write this SQL query? And am I even going about the database architecture the right way?

Answer 1

As it turns out, neither of these answers were right. @jam6459 was closest.

The correct answer is the following:

SELECT userdata.text, userdata.image, follows.userFollow
  FROM userdata
  LEFT JOIN follows ON follows.userFollow = userdata.username
  WHERE follows.userId = $username

I also found it easier to not have a username correspond to an Id as in jam’s table example. This is because the same user can have multiple entries in “USERDATA”. I instead used username as the Id.