MySQL 8.0

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DROP TABLE IF EXISTS pre_forum_post;
CREATE TABLE pre_forum_post (
pid int(10) unsigned NOT NULL,
fid mediumint(8) unsigned NOT NULL DEFAULT '0',
tid mediumint(8) unsigned NOT NULL DEFAULT '0',
`first` tinyint(1) NOT NULL DEFAULT '0',
author varchar(15) NOT NULL DEFAULT '',
authorid mediumint(8) unsigned NOT NULL DEFAULT '0',
`subject` varchar(80) NOT NULL DEFAULT '',
dateline int(10) unsigned NOT NULL DEFAULT '0',
message mediumtext NOT NULL,
useip varchar(15) NOT NULL DEFAULT '',
`port` smallint(6) unsigned NOT NULL DEFAULT '0',
invisible tinyint(1) NOT NULL DEFAULT '0',
anonymous tinyint(1) NOT NULL DEFAULT '0',
usesig tinyint(1) NOT NULL DEFAULT '0',
htmlon tinyint(1) NOT NULL DEFAULT '0',
bbcodeoff tinyint(1) NOT NULL DEFAULT '0',
smileyoff tinyint(1) NOT NULL DEFAULT '0',
parseurloff tinyint(1) NOT NULL DEFAULT '0',
attachment tinyint(1) NOT NULL DEFAULT '0',
rate smallint(6) NOT NULL DEFAULT '0',
ratetimes tinyint(3) unsigned NOT NULL DEFAULT '0',
`status` int(10) NOT NULL DEFAULT '0',
tags varchar(255) NOT NULL DEFAULT '0',
`comment` tinyint(1) NOT NULL DEFAULT '0',
replycredit int(10) NOT NULL DEFAULT '0',
position int(8) unsigned NOT NULL AUTO_INCREMENT,
PRIMARY KEY (tid,position),
UNIQUE KEY pid (pid),
KEY fid (fid),
KEY authorid (authorid,invisible),
KEY dateline (dateline),
KEY invisible (invisible),
KEY displayorder (tid,invisible,dateline),
KEY `first` (tid,`first`)
) TYPE=MyISA

DELETE FROM pre_forum_post 
WHERE (tid, position) IN (
  SELECT tid, position 
  FROM pre_forum_post 
  WHERE `authorid` = 1111118);