public function getDoctrineTypeMapping($dbType)
    {
        if ($this->doctrineTypeMapping === null) {
            $this->initializeAllDoctrineTypeMappings();
        }

        $dbType = strtolower($dbType);

        if (! isset($this->doctrineTypeMapping[$dbType])) {
            throw new DBALException('Unknown database type ' . $dbType . ' requested, ' . static::class . ' may not support it.');
        }

        return $this->doctrineTypeMapping[$dbType];
    }