====== Expression Engine Installation and Upgrade Problems ====== This is a list of some problems and solutions I have come across when installing or upgrading Expression Engine. ===== Table ‘xxx’ already exists =====

Error Number: 1050

Description: Table ‘exp_member_search’ already exists

Query: CREATE TABLE `exp_member_search` ( `search_id` varchar(32) NOT NULL, `search_date` int(10) unsigned NOT NULL,
`keywords` varchar(200) NOT NULL, `fields` varchar(200) NOT NULL, `member_id` int(10) unsigned NOT NULL, `ip_address`
varchar(16) NOT NULL, `total_results` int(8) unsigned NOT NULL, `query` text NOT NULL, PRIMARY KEY (`search_id`), KEY
`member_id` (`member_id`) ) 

The problem occurs during upgrade. The upgrade script found under system/updates/###.php is being run twice. There are a couple of reasons I've come across for this.

1. the stepping in config.php didn't get updated during a previous update. Look at the value $conf['app_version'] = ”###”;. If the version number is less than the upgrade you are trying to perform older scripts will get rerun. Check the permissions on config.php and adjust the version number. In detail a database update is occuring and finding that the update has already been performed and failing.
2. Slightly more obscure. You may run your website on more than one server. Say a development and production machine. You have updated the production machine. Copied the production database (which has been updated) to your development system and then tried to update your development system.

===== Uncleared Caches ===== Failing to clear your SQL cache throught the ExpressionEngine control panel before an update can result in strange database errors when you connect to the site. Old database queries are being run on updated tables. The update may have added or removed columns and this can cause errors. The solution is to go into the system/cache directory and manually delete all the cache files. Make sure that the directories are writable by ExpressionEngine.