the following notes should help to solve the problem.
#0 vendor/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(701): Doctrine\DBAL\DBALException::driverExceptionDuringQuery(Object(PDOException), 'SELECT DISTINCT...', Array) #1 vendor/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php(204): Doctrine\DBAL\Connection->executeQuery('SELECT DISTINCT...', Array, Array) #2 engine/core/class/sArticles.php(1813): Doctrine\DBAL\Query\QueryBuilder->execute() #3 engine/core/class/sArticles.php(1700): sArticles->getFilterSortMode(9, 1, Array) #4 engine/core/class/sArticles.php(1855): sArticles->getCategoryFilters(9, Array, 0) #5 Shopware/Controllers/Frontend/Listing.php(204): sArticles->sGetCategoryProperties(9, NULL, NULL) #6 Enlight/Controller/Action.php(159): Shopware_Controllers_Frontend_Listing->indexAction() #7 Enlight/Controller/Dispatcher/Default.php(528): Enlight_Controller_Action->dispatch('indexAction') #8 Enlight/Controller/Front.php(228): Enlight_Controller_Dispatcher_Default->dispatch(Object(Enlight_Controller_Request_RequestHttp), Object(Enlight_Controller_Response_ResponseHttp)) #9 Shopware/Kernel.php(141): Enlight_Controller_Front->dispatch() #10 vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpCache/HttpCache.php(472): Shopware\Kernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #11 Shopware/Components/HttpCache/AppCache.php(256): Symfony\Component\HttpKernel\HttpCache\HttpCache->forward(Object(Symfony\Component\HttpFoundation\Request), true, NULL) #12 vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpCache/HttpCache.php(429): Shopware\Components\HttpCache\AppCache->forward(Object(Symfony\Component\HttpFoundation\Request), true) #13 vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpCache/HttpCache.php(329): Symfony\Component\HttpKernel\HttpCache\HttpCache->fetch(Object(Symfony\Component\HttpFoundation\Request), true) #14 Shopware/Components/HttpCache/AppCache.php(178): Symfony\Component\HttpKernel\HttpCache\HttpCache->lookup(Object(Symfony\Component\HttpFoundation\Request), true) #15 vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpCache/HttpCache.php(193): Shopware\Components\HttpCache\AppCache->lookup(Object(Symfony\Component\HttpFoundation\Request), true) #16 Shopware/Components/HttpCache/AppCache.php(113): Symfony\Component\HttpKernel\HttpCache\HttpCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #17 shopware.php(109): Shopware\Components\HttpCache\AppCache->handle(Object(Symfony\Component\HttpFoundation\Request)) #18 {main}