[General] Problem restoring backup from earlier version

[nixer55]

You can point at the old database in the aforementioned inc/config.php, but don't think that will solve all your problems.  You're trying to restore 1820 data into a 1822 release.  Some things will be different - like templates - even on a bone stock installation.  And that stuff is in the database.

Personally, I'd never try to upgrade in this manner.  Would follow the MyBB Upgrade instructions and do it in place.  I've been distracted by the mysql technicalities of this exercise and guilty of losing sight of the main goal.  Not sure this can be done with the anticipated results.  Because of the version differences.

I know how I'd proceed, but too many questions regarding your previous installation remain unclear.  Might do more harm then good to elaborate.  Leaving this one to the experts.

cheers...

[lemnoc]

You can point at the old database in the aforementioned inc/config.php, but don't think that will solve all your problems.  You're trying to restore 1820 data into a 1822 release.  Some things will be different - like templates - even on a bone stock installation.  And that stuff is in the database.

Personally, I'd never try to upgrade in this manner.  Would follow the MyBB Upgrade instructions and do it in place.  I've been distracted by the mysql technicalities of this exercise and guilty of losing sight of the main goal.  Not sure this can be done with the anticipated results.  Because of the version differences.

I know how I'd proceed, but too many questions regarding your previous installation remain unclear.  Might do more harm then good to elaborate.  Leaving this one to the experts.

cheers...

I just tried to manually reinstall 18.1.9 from scratch and can't properly restore the database in that either without some obscure database error ? What's the point in doing a backup if it is so difficult to restore a backup ?

Error
SQL query:

-- MyBB Database Backup
-- Generated: 02nd April 2019 at 05:34
-- -------------------------------------

CREATE TABLE `mybb_adminlog` (
  `uid` int(10) unsigned NOT NULL DEFAULT '0',
  `ipaddress` varbinary(16) NOT NULL DEFAULT '',
  `dateline` int(10) unsigned NOT NULL DEFAULT '0',
  `module` varchar(50) NOT NULL DEFAULT '',
  `action` varchar(50) NOT NULL DEFAULT '',
  `data` text NOT NULL,
  KEY `module` (`module`,`action`),
  KEY `uid` (`uid`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

MySQL said: 

#1050 - Table 'mybb_adminlog' already exists

[ Back ]

[nixer55]

First - thought you said the backup was done from 1.8.20 - then why restoring to 1.8.19?  Guess you have no attachments on your system either - otherwise you really should have the files as well.  MyBB database backup is just that, database only.

Second, that's far from an obscure error.  The "tables exist" error is because the mysql dump was not done with the "add drop table" instruction.  i.e.  "mysqldump --add-drop-table".  Which is normal for MyBB backups I believe.  No big problem, you can get around that.

Mentioned before - restoring to an existing and populated database can be problematic.  If you're trying to restore in this manner, you'll need to drop the existing tables first. This is easily done in phpmyadmin.

These are fairly basic things, so expect you might need a little help.  Reluctant to suggest anything with actually seeing it.

Good luck...