Database Exception – yii\db\Exception

                                    } else {                    $this->pdoStatement->execute();                }                break;            } catch (\Exception $e) {                $rawSql = $rawSql ?: $this->getRawSql();                $e = $this->db->getSchema()->convertException($e, $rawSql);                if ($this->_retryHandler === null || !call_user_func($this->_retryHandler, $e, $attempt)) {                    throw $e;                }            }        }    }                

                             $this->prepare(true);         try {            $profile and Yii::beginProfile($rawSql, 'yii\db\Command::query');             $this->internalExecute($rawSql);             if ($method === '') {                $result = new DataReader($this);            } else {                if ($fetchMode === null) {                    $fetchMode = $this->fetchMode;                

                         * @return array|false the first row (in terms of an array) of the query result. False is returned if the query     * results in nothing.     * @throws Exception execution failed     */    public function queryOne($fetchMode = null)    {        return $this->queryInternal('fetch', $fetchMode);    }     /**     * Executes the SQL statement and returns the value of the first column in the first row of data.     * This method is best used when only a single value is needed for a query.     * @return string|null|false the value of the first column in the first row of the query result.                

                        public function one($db = null)    {        if ($this->emulateExecution) {            return false;        }         return $this->createCommand($db)->queryOne();    }     /**     * Returns the query result as a scalar value.     * The value returned will be the first column in the first row of the query results.     * @param Connection $db the database connection used to generate the SQL statement.                

                         * @return ActiveRecord|array|null a single row of query result. Depending on the setting of [[asArray]],     * the query result may be either an array or an ActiveRecord object. `null` will be returned     * if the query results in nothing.     */    public function one($db = null)    {        $row = parent::one($db);        if ($row !== false) {            $models = $this->populate([$row]);            return reset($models) ?: null;        }         return null;                

                                    break;            }        }         $result = null;         if ($runAction && $this->beforeAction($action)) {            // run the action            $result = $action->runWithParams($params);             $result = $this->afterAction($action, $result);             // call afterAction on modules                

                            $parts = $this->createController($route);        if (is_array($parts)) {            /* @var $controller Controller */            list($controller, $actionID) = $parts;            $oldController = Yii::$app->controller;            Yii::$app->controller = $controller;            $result = $controller->runAction($actionID, $params);            if ($oldController !== null) {                Yii::$app->controller = $oldController;            }             return $result;        }                

                                $params = $this->catchAll;            unset($params[0]);        }        try {            Yii::debug("Route requested: '$route'", __METHOD__);            $this->requestedRoute = $route;            $result = $this->runAction($route, $params);            if ($result instanceof Response) {                return $result;            }             $response = $this->getResponse();            if ($result !== null) {                

                        {        try {            $this->state = self::STATE_BEFORE_REQUEST;            $this->trigger(self::EVENT_BEFORE_REQUEST);             $this->state = self::STATE_HANDLING_REQUEST;            $response = $this->handleRequest($this->getRequest());             $this->state = self::STATE_AFTER_REQUEST;            $this->trigger(self::EVENT_AFTER_REQUEST);             $this->state = self::STATE_SENDING_RESPONSE;            $response->send();