TYPO3 Core

Hey,

I'm using TYPO3 7.6.16 and PostgreSQL 9.6.2.

Whenever I execute a scheduler task I get an exception

Argument 1 passed to TYPO3\CMS\Dbal\Database\DatabaseConnection::_quoteGroupBy() must be of the type array, string given, called in /typo3_src-7.6.16/typo3/sysext/dbal/Classes/Database/DatabaseConnection.php on line 1876

The reason for this is that the scheduler does not pass all expected parameters to the database method.

»/typo3/sysext/scheduler/Classes/Scheduler.php« (fetchTask, line 269) does pass an array with SELECT, FROM, WHERE and LIMIT to the database method »exec_SELECT_queryArray«.

»/typo3/sysext/core/Classes/Database/DatabaseConnection.php« (queryArray, line 358) uses all possible array keys and passes them to the »exec_SELECTquery« method. If the previous method did not provide one of the keys then »NULL« will be passed instead. In PostgreSQL this will cause the exception shown above.

Solution 1: Pass all possible array keys / parameters in the original method. E.g.

            $queryArray = [
                'SELECT' => 'uid, serialized_task_object',
                'FROM' => 'tx_scheduler_task',
                'WHERE' => 'uid = ' . (int)$uid,
                'GROUPBY' => '',
                'ORDERBY' => '',
                'LIMIT' => 1
            ];

Solution 2: We saw, that this error occured several times before, e.g: #76991 Instead of fixing the origin it may be a good idea to fix the »exec_SELECT_queryArray« and make sure, that this one passes all optional keys with a least an empty string. This means, that the method has to check for the existance of the optional keys. E.g.

        $queryPartsFallback = [
            'GROUPBY' => '',
            'ORDERBY' => '',
            'LIMIT' => ''
        ];
        $queryParts = array_merge($queryPartsFallback, $queryParts);
        return $this->exec_SELECTquery($queryParts['SELECT'], $queryParts['FROM'], $queryParts['WHERE'], $queryParts['GROUPBY'], $queryParts['ORDERBY'], $queryParts['LIMIT']);

The bug appears in 7.6 and 6.2