Laravel 5 mongo DB的倍增列的Eloquent总和

我相信聚合运算符sum会将精确的列名称作为参数.您可以先尝试project乘法,然后对结果求和:

DB::connection($this->MongoSchemaName)
    ->collection($this->InvoicesTable)
    ->where('ContactID', (int)$customer->ContactID)
    ->project([
        'ContactID' => 1, 
        'TotalInBaseCurrency' => ['$multiply' => ['$Total', '$CurrencyRate']]
    ])
    ->sum('TotalInBaseCurrency')

或直接使用聚合:

DB::connection($this->MongoSchemaName)
    ->collection($this->InvoicesTable)
    ->raw(function($collection) use ($customer){
        return $collection->aggregate([
            ['$match' => [
                    'ContactID' => (int)$customer->ContactID,
                    'Type' => 'PAYMENT'
                ]
            ],
            ['$group' => [
                '_id' => '$ContactID',
                'TotalInBaseCurrency' => [
                        '$sum' => ['$multiply' => ['$Total', '$CurrencyRate']]
                    ]
                ]
            ]
        ]);
    })