在不更改 sql mode=only_full_group_by 模式的情况下如何在 cakephp 中执行 group by？

Question

我正在尝试从交易表中获取每月的金额总和。我在 cakephp 函数下面写了我想要的输出。

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;
 }

我遇到了错误

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

不改变sql模式，如何在这里运行group by？

Answer 1

改为按聚合排序。

由于您按月份分组，因此这些组中的所有 created 字段将属于同一月份，例如，一组中的所有 created 字段将指向比另一个组，因此您可以简单地从组中选择最小值或最大值：

->orderAsc(function (
    \Cake\Database\Expression\QueryExpression $exp,
    \Cake\ORM\Query $query
) {
    return $query->func()->min(
        $query->identifier('Transactions.created')
    );
})

ORDER BY MIN(Transactions.created) ASC

此外，如果您将月份选择为数字而不是名称，则可以在该字段中进行排序。