/**
  * @return \yii\db\ActiveQuery
  */
 public function getCustomerUserNames()
 {
     return $this->hasMany(Customer::className(), ['customer_user_name' => 'customer_user_name'])->viaTable('cart', ['item_id' => 'item_id']);
 }
 /**
  * @return \yii\db\ActiveQuery
  */
 public function getCustomerUserName()
 {
     return $this->hasOne(Customer::className(), ['customer_user_name' => 'customer_user_name']);
 }