I tried to upgrade my Magento installation from 22.214.171.124 to 126.96.36.199 using every way I could imagine, but still running into the “table or view already exists” exception. So what is happening here?
My first view into the upgrade process shows me, that there is a table in Magento keeping track of the data and entity_version, called core_config_data. The system checks the entries here with the current version of the modules installed. No matter what you did, at one point Magento descides to upgrade your system with this mechanism.
If I looked into the upgrade files, for example app/code/core/Mage/Sales/sql/sales_setup/mysql4-upgrade-188.8.131.52-184.108.40.206.php that ran into the problem, I regconized that there must be a mistake, maybe a bug. The script tries to create table that are still exists. This is not the only update script that runs into this problem.
Someone can hack it by replacing CREATE TABLE with CREATE TABLE IF NOT EXISTS, if the table structure would be the same.
I wonder why this error occurs.