troubleshooting Question

Issue with SQL statement in MySQL and MariaDB

Avatar of Adebayo Ojo
Adebayo OjoFlag for Nigeria asked on
DatabasesSQL
6 Comments1 Solution143 ViewsLast Modified:
I have the below SQL statement which works as expected on my local machine WAMP server using MySQL, but when I upload to the live server using MariaDB, it doesn't work as expected anymore. The SQL statement is used for post and comment display. Any post or comment with latest postdate should be on top of the displayed list. As I said, it worked perfectly with MySQL on my local WAMP server, but when I upload to live server using MariaDB, no matter what I tried, it reverses the order by showing latest post/comment at the bottom of the list and old post/comments at the top. Please help me as I'm now confused on why it's behaving this way.

The SQL statement is shown below:

SELECT * FROM 
(SELECT once.id, message, audio, audio_desc, accepted, postdate, tag, broadcast, once.mobile, once.username1, state, users.username, users.firstname, users.lastname, users.fullname, users.avatar, users.alias, useroptions.aliascheck, content_provider.content_type, comment.comment_date as c1 FROM once LEFT OUTER JOIN users ON once.username1 = users.username INNER JOIN useroptions ON once.username1 = useroptions.username LEFT OUTER JOIN content_provider ON once.username1 = content_provider.provider LEFT JOIN comment ON once.id = comment.post_id AND once.tag = comment.post_tag WHERE once.username1='logusername' OR once.username1='myusername'
UNION ALL
SELECT daily.id, message, audio, audio_desc, accepted, postdate, tag, broadcast, daily.mobile, daily.username1, state, users.username, users.firstname, users.lastname, users.fullname, users.avatar, users.alias, useroptions.aliascheck, content_provider.content_type, comment.comment_date as c1 FROM daily LEFT OUTER JOIN users ON daily.username1 = users.username INNER JOIN useroptions ON daily.username1 = useroptions.username LEFT OUTER JOIN content_provider ON daily.username1 = content_provider.provider LEFT JOIN comment ON daily.id = comment.post_id AND daily.tag = comment.post_tag WHERE daily.username1='logusername' OR daily.username1='myusername'
UNION ALL
SELECT weekly.id, message, audio, audio_desc, accepted, postdate, tag, broadcast, weekly.mobile, weekly.username1, state, users.username, users.firstname, users.lastname, users.fullname, users.avatar, users.alias, useroptions.aliascheck, content_provider.content_type, comment.comment_date as c1 FROM weekly LEFT OUTER JOIN users ON weekly.username1 = users.username INNER JOIN useroptions ON weekly.username1 = useroptions.username LEFT OUTER JOIN content_provider ON weekly.username1 = content_provider.provider LEFT JOIN comment ON weekly.id = comment.post_id AND weekly.tag = comment.post_tag WHERE weekly.username1='logusername' OR weekly.username1='myusername') outerQueryName GROUP BY id ORDER BY COALESCE(GREATEST(postdate, MAX(c1)), postdate) DESC
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