modified unique validation

common/models/District.php

@@ -56,7 +56,7 @@ class District extends \yii\db\ActiveRecord
     {
         return [
             [['state_id', 'name'], 'required'],
-            [['name'], 'unique'],
+            ['name', 'unique', 'targetAttribute' => ['name', 'state_id']],
             [['state_id', 'status', 'created_at', 'updated_at'], 'integer'],
             [['name', 'slug'], 'string', 'max' => 1024],
             [['state_id'], 'exist', 'skipOnError' => true, 'targetClass' => State::className(), 'targetAttribute' => ['state_id' => 'id']],