code review changes

common/migrations/db/m160830_105840_category.php

 <?php
-
 use yii\db\Migration;
+use common\models\Category;
 
 class m160830_105840_category extends Migration
 {
- /*   public function up()
-    {
-
-    }
-
-    public function down()
-    {
-        echo "m160830_105840_category cannot be reverted.\n";
-
-        return false;
-    }*/
 
     public function safeUp()
     {
@@ -29,9 +18,8 @@ class m160830_105840_category extends Migration
             'slug' => $this->string(32)->notNull(),
             'description' => $this->string(512),
             'image_url' => $this->string(1024),
-            'image_path' =>  $this->string(1024),
-            'status' => $this->smallInteger()->notNull(),
-            //->defaultValue(Category::STATUS_ACTIVE),
+            'image_path' => $this->string(1024),
+            'status' => $this->smallInteger()->notNull()->defaultValue(Category::STATUS_ACTIVE),
             'created_at' => $this->integer(),
             'updated_at' => $this->integer()
         ], $tableOptions);
@@ -40,13 +28,14 @@ class m160830_105840_category extends Migration
             'id' => $this->primaryKey(),
             'category_id' => $this->integer()->notNull(),
             'code' => $this->string(32)->notNull(),
-            'type' => $this->string(32),
-            'name' => $this->string(32),
+            'type' => $this->string(32)->notNull(),
+            'name' => $this->string(32)->notNull(),
             'created_at' => $this->integer(),
             'updated_at' => $this->integer()
         ], $tableOptions);
 
-        $this->addForeignKey('fk_category', '{{%category_files}}', 'category_id', '{{%category}}', 'id', 'cascade', 'cascade');
+        $this->addForeignKey('fk_category', '{{%category_files}}', 'category_id', '{{%category}}', 'id', 'cascade',
+            'cascade');
     }
 
     public function safeDown()