Problem
The following error occurs:
Fatal error: Call to undefined method Varien_Db_Adapter_Pdo_Mysql::insertIgnore() in [...]/app/code/community/Dhl/OnlineRetoure/data/dhlonlineretoure_setup/data-upgrade-15.07.16-15.10.29.php on line 33
Cause
Most likely, an older Magento version is being used (e.g. 1.7.x). The command "insertIgnore" is not available there.
Solution
Edit the file
app/code/community/Dhl/OnlineRetoure/data/dhlonlineretoure_setup/data-upgrade-15.07.16-15.10.29.php
In line 33 it says:
$installer->getConnection()->insertIgnore($table, array(
Change it to this:
$installer->getConnection()->insertOnDuplicate($table, array(