如何根据另外两个表的计算从一个表中检索数据？

Question

假设我有三个名为Customer ,Invoice和Payment 。 发票和付款模式看起来像

id , customer_id, amount

我想只获得那些具有这些金额差异的Invoice.sum(amount)>Payment.sum(amount)客户

我目前正在检索

$customers=Customer::get();
foreach($customers as $customer)
{  
  $pay=Payment::where('customer_id',$customer->id)->sum('amount');
  $due=Invoice::where('customer_id',$customer->id)->sum('amount');
  if($due>$pay){
   // showing this customers 
   }
}

雄辩的加入有没有更好的方法？ 我怎样才能得到laravel雄辩？

Answer 1

您是否在模型中设置了任何关系？ 更好的雄辩查询将如下所示。 您可能需要稍微调整一下

Customer::join('payment','customer.id','=','payment.customer_id')
          ->join('invoice','customer.id','=','invoice.customer_id')
          ->select(array('customer.*'),DB::raw("SUM(payment.amount) as payment_sum,SUM(invoice.amount) as invoice_sum"))
          //->where('customer_id',$customer->id)
          ->groupBy('customer.id')  //replace with anything that make sense for you.
          ->havingRaw('invoice_sum > payment_sum')
          ->get();

Answer 2

尝试这个

首先，在您的Customer模型中定义关系

public function payments()
{
  return $this->hasMany(Payment::class); //based on your logic or structure
}

public function invoices()
{
  return $this->hasMany(Invoice::class); //based on your logic or structure
}

Customer::with(['payments' => function($query) {
               $query->sum('amount');
         }])
        ->get();

要么

$customers=Customer::with('payments','invoices')->get();
foreach($customers as $customer)
{  
  $pay = $customer->payments()->sum('amount');
  $due = $customer->invoices()->sum('amount');

   //other logic
}