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POOrder data within group by that has 2 different columns in MySQL
 

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  1. POOrder data within group by that has 2 different columns in MySQL
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    <p>I am working with a discussion board where there will be a certain topic and the user can comment or upvote another comment. Each comment can also be replied by another user and will recieve notifications.</p> <h3>My notification table</h3> <ul> <li><code>notification_id</code> is the user_id of the logged in user that will receive the notification</li> <li><code>notification_from</code> is the user_id of the one who commented or like the users post.</li> <li><code>notification_topic</code> is the id of the topic plus the type of notification that will distinguish if it is a comment or an upvote</li> <li><code>notification_comment</code> is the comment_id in the topic</li> </ul> <pre> +-----------------+-------------------------+-------------------+--------------------------------------+----------------------+-------------------+-------------------+--------------------+----------------------+---------+--------+ | notification_id | notification_pic | notification_name | notification_title | notification_user_id | notification_date | notification_from | notification_topic | notification_comment | type | status | +-----------------+-------------------------+-------------------+--------------------------------------+----------------------+-------------------+-------------------+--------------------+----------------------+---------+--------+ | 1 | 32_1380182434_thumb.jpg | Sheena Salazar | Chrysler files papers for share sale | 2 | 1380188338 | 32 | 83_upvote | 1 | upvote | read | | 2 | 32_1380182434_thumb.jpg | Sheena Salazar | Chrysler files papers for share sale | 2 | 1380188342 | 32 | 83_comment | 1 | comment | read | | 3 | 93_1379990163_thumb.jpg | vhon samson | Chrysler files papers for share sale | 2 | 1380188505 | 93 | 83_upvote | 1 | upvote | read | | 4 | 93_1379990163_thumb.jpg | vhon samson | Chrysler files papers for share sale | 2 | 1380188509 | 93 | 83_comment | 1 | comment | read | | 5 | 93_1379990163_thumb.jpg | vhon samson | Chrysler files papers for share sale | 0 | 1380246975 | 93 | 83_comment | 1 | comment | unread | | 6 | 93_1379990163_thumb.jpg | vhon samson | Toyota and Nissan in vehicle recall | 2 | 1380247149 | 93 | 225_comment | 3 | comment | read | | 7 | default.gif | kath aguilar | Chrysler files papers for share sale | 2 | 1380253584 | 7 | 83_comment | 1 | comment | read | | 8 | default.gif | kath aguilar | Chrysler files papers for share sale | 93 | 1380253870 | 7 | 83_comment | 2 | comment | unread | +-----------------+-------------------------+-------------------+--------------------------------------+----------------------+-------------------+-------------------+--------------------+----------------------+---------+--------+ </pre> <h3>My query</h3> <p>This is how I query and group my table:</p> <pre class="lang-sql prettyprint-override"><code>SELECT *, COUNT(notification_topic) AS topic_count FROM tbl_notification WHERE notification_user_id = '{$_SESSION['id']}' GROUP BY notification_topic ORDER BY notification_date DESC LIMIT 8 </code></pre> <p>This is the result of the query:</p> <pre> +-----------------+-------------------------+-------------------+--------------------------------------+----------------------+-------------------+-------------------+--------------------+----------------------+---------+--------+-------------+ | notification_id | notification_pic | notification_name | notification_title | notification_user_id | notification_date | notification_from | notification_topic | notification_comment | type | status | topic_count | +-----------------+-------------------------+-------------------+--------------------------------------+----------------------+-------------------+-------------------+--------------------+----------------------+---------+--------+-------------+ | 6 | 93_1379990163_thumb.jpg | vhon samson | Toyota and Nissan in vehicle recall | 2 | 1380247149 | 93 | 225_comment | 3 | comment | read | 1 | | 2 | 32_1380182434_thumb.jpg | Sheena Salazar | Chrysler files papers for share sale | 2 | 1380188342 | 32 | 83_comment | 1 | comment | read | 3 | | 1 | 32_1380182434_thumb.jpg | Sheena Salazar | Chrysler files papers for share sale | 2 | 1380188338 | 32 | 83_upvote | 1 | upvote | read | 2 | +-----------------+-------------------------+-------------------+--------------------------------------+----------------------+-------------------+-------------------+--------------------+----------------------+---------+--------+-------------+ </pre> <p>See it on <a href="http://sqlfiddle.com/#!2/aad545/1/0" rel="nofollow noreferrer">sqlfiddle</a>.</p> <h3>What I need</h3> <p>I need to get the count so that I can come up with a notification like on facebook, like this:</p> <p><img src="https://i.stack.imgur.com/oFwf6.jpg" alt="enter image description here"></p> <p>My main problem is I can't <code>ORDER</code> it by <code>notification_date</code> before the <code>GROUP BY</code> because I need to isolate each <code>notification_comment</code> by its <code>notification_topic</code>. I want the latest user that commented or like each topic to be displayed. How will I do this?</p>
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    1. USJoem Maranan
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