complete the model, controller, and migration

database/migrations/2018_05_15_034032_create_soitems_table.php

@@ -16,6 +16,14 @@ class CreateSoitemsTable extends Migration
         Schema::create('soitems', function (Blueprint $table) {
             $table->increments('id');
 
+            // foreign key for the so table
+            $table->unsignedInteger('so_id');
+            $table->foreign('so_id')
+               ->references('id')->on('sos')
+               ->onDelete('cascade')
+               ->onUpdate('cascade');
+            $table->Integer('status')->default('0');
+
             //Item details
             $table->integer('order_id');
             $table->integer('brand_no');