我有兩個表“發票”，其中“invoice_no”作為主鍵，“invoice_details”以“invoice_no”作為外鍵。我想使用 Laravel 同時將數據插入到兩個表中。問題是當我提交表單時，數據被存儲到發票表中，但沒有存儲到invoice_details中，這給了我外鍵為空的完整性約束違規錯誤。這是控制器代碼：public function insertInv(Request $request){                //insert into invice        $customer_name = $request->input('customer_name');        $c_email = $request->input('c_email');        $c_phone = $request->input('c_phone');        $billing_address = $request->input('billing_address');        $term = $request->input('term');        $order_date = $request->input('order_date');        $due_date = $request->input('due_date');        $discount = $request->input('discount');        $net_total = $request->input('net_total');        $paid = $request->input('paid');        $due = $request->input('due');        $payment_type = $request->input('payment_type');        $invoice_msg = $request->input('invoice_msg');                //insert into invoice_details        $invoice_no = $request->input('invoice_no');        $product_name = $request->input('state');        $inven_name = $request->input('country');        $unit = $request->input('unit');        $price = $request->input('price');        $qty = $request->input('cqty');        $sub_total = $request->input('sub_total');        //insert into invoice        $invo=array('customer_name'=>$customer_name,'c_email'=>$c_email,'c_phone'=>$c_phone,'billing_address'=>$billing_address,'term'=>$term,'order_date'=>$order_date,'due_date'=>$due_date,'discount'=>$discount,'net_total'=>$net_total,'paid'=>$paid,'due'=>$due,'payment_type'=>$payment_type,'invoice_msg'=>$invoice_msg );        DB::table('invoice')->insert($invo);                //insert into invoice_details        $invo_det=array('invoice_no'=>$invoice_no,'product_name'=>$product_name,'inven_name'=>$inven_name,'unit'=>$unit,'price'=>$price,'qty'=>$qty,'sub_total'=>$sub_total);        DB::table('invoice_details')->insert($invo_det);                     return redirect()->back();}