我正在尝试从交易表中得到每月的金额总和。我已经在下面写了cakephp函数来得到我想要的输出。

public function getLastSixMOnthsExpenses($since_date, $t_type)
{
           $query = $this->find()->select([
                 'month' => $this->find()->func()->monthname([
                   'created' => 'identifier'
                ]),
               'amount' => $this->find()->func()->sum('Transactions.amount')
            ])
            ->where([
               'Transactions.created >='=>  $since_date->modify('6 months ago')->startOfMonth(),
               'Transactions.created <='=>  $since_date->endOfMonth(),
               'Transactions.transaction_type '=>$t_type
            ])
            ->group(['month'])
            ->order(['Transactions.created'=>'ASC'])
           ;

           return $query;
 }

我遇到以下错误

Syntax error or access violation: 1055 Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column 'kjoumaa_kamaljoumaa.Transactions.created' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

在不改变sql模式的情况下，如何在此处运行group by？