Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I'm assuming a few things, if they're not correct you'll have to modify this stuff but if I'm right, these operations won't need any <code>JOIN</code>s:</p> <ol> <li><code>$userSession</code> variable contains the user who's logged in's ID.</li> <li><code>$userToView</code> variable contains the user who he's trying to view's ID.</li> <li>Your database structure will only have one entry for the two users who are friends, so we have to check both combinations.</li> </ol> <p>To determine if the user is a friend:</p> <pre><code>SELECT user_a, user_b FROM friends WHERE (user_a = $userSession AND user_b = $userToView) OR (user_a = $userToView AND user_b = $userSession) LIMIT 1; </code></pre> <p>Then you'd use an <code>if</code> statement in PHP (it's usually better to keep business logic in the application, rather than in the database), if it's true return the posts.</p> <pre><code>$results = $mysqli-&gt;query($query)-&gt;fetch_row(); if($results) { ... return posts ... } else { echo 'Not friends'; } </code></pre> <p>That would be a query something like this:</p> <pre><code>SELECT * FROM posts WHERE user = $userToView; </code></pre> <p>You will need to read up about <a href="http://php.net/manual/en/book.mysqli.php" rel="nofollow">mysqli</a> (do not use mysql plugin, it's deprecated) and about <a href="http://php.net/manual/en/security.database.sql-injection.php" rel="nofollow">SQL injection attacks</a> and how to prevent them. It may sound like a hassle, but it's far less daunting to understand this stuff than to deal with the fallout if you don't.</p>
    singulars
    1. This table or related slice is empty.
    1. POSocial Network SQL statement for posts
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USGlitch Desire
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COThanks, I have already moved over to PDO. Did it a few months back and it was a truly great move, much more can be done with it and it s just infinitely better than the MySQL_* functions, thanks for example SQL syntax! I didn't think it would be that simple, now if I was to grab USER_B's information within the same statement, would that require a join? Since I will be fetching data from another table?
      singulars
      1. PO
      1. USJake Ball
    2. CONo problem, hope it helps.
      singulars
      1. PO
      1. USGlitch Desire
    3. CO@JakeBall - If you wanted to get data from 2 tables at the same time (in a single query), that would require a `JOIN`. If, for example, you had the user's `id` as primary key in `posts` and `users`, but you needed their `real_name` from `users` table, and `post` from `posts` table, you would use a `JOIN`.
      singulars
      1. PO
      1. USGlitch Desire
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload