Drupal 7 problem: Class ‘MergeQuery_mysql’ not found
This is a quick note of frustration about a problem into which I’ve been running mercilessly. I have a site on Drupal 7.0, that I have been trying to upgrade to the new 7.4 release. As preparation, I’ve taken two different development sites through the same upgrade, and the dev sites moved fine. With the real site, however, I run into the following scenario:
- Make backup
- Put site in maintenance mode
- Delete all 7.0 files/folders
- Unpack all 7.4 files/folders other than the /sites directory
- Copy the old connection string to the new default.settings.php file, save as settings.php
At this point, the site works, and the status board shows green – with the warning that some updates need to be done to the schema. So, I go to update.php.
And…the site breaks. Hard. White Screen of Death hard. Update.php fails, the site root fails, everything.
So, I throw on the three lines of debugging code from http://drupal.org/node/158043 to peek under the hood and see what I can find.
This is the output: Notice: require_once() [function.require-once]: 1. h->opened_path=[E:\sites\knowlton-stage.96\includes\bootstrap.inc] h->filename=[E:\sites\knowlton-stage.96/includes/bootstrap.inc] in E:\sites\knowlton-stage.96\index.php on line 23 Notice: require_once() [function.require-once]: 1. h->opened_path=[E:\sites\knowlton-stage.96\includes\errors.inc] h->filename=[E:\sites\knowlton-stage.96/includes/errors.inc] in E:\sites\knowlton-stage.96\includes\bootstrap.inc on line 1971 Notice: require_once() [function.require-once]: 1. h->opened_path=[E:\sites\knowlton-stage.96\includes\common.inc] h->filename=[E:\sites\knowlton-stage.96/includes/common.inc] in E:\sites\knowlton-stage.96\includes\errors.inc on line 73 Notice: require_once() [function.require-once]: 1. h->opened_path=[E:\sites\knowlton-stage.96\includes\unicode.inc] h->filename=[E:\sites\knowlton-stage.96/includes/unicode.inc] in E:\sites\knowlton-stage.96\includes\common.inc on line 1557 Fatal error: Class 'MergeQuery_mysql' not found in E:\sites\knowlton-stage.96\includes\database\database.inc on line 826
I’ve done what I consider a fair amount of Googling, both within the WSOD error and the MergeQuery_mysql function. Nothing has worked. I have backups, and obviously a dev site – but I’m a bit flummoxed as to why I’m seeing this error. Any input on this would be greatly appreciated.