Yii2 rest api join query with ActiveDataProvider - php

Question

I have a custom action in ActiveController and need to fetch some data by joining two tables.
I have written following query .
$query = Item::find()->joinWith(['subcategory'])->select(['item.*', 'sub_category.name'])->where(['item.active' => 1])->addOrderBy(['item.id' => SORT_DESC]);
$pageSize = (isset($_GET["limit"]) ? $_GET["limit"] : 1) * 10;
$page = isset($_GET["page"]) ? $_GET["page"] : 1;
$dataProvider = new ActiveDataProvider(['query' => $query, 'pagination' => ['pageSize' => $pageSize, "page" => $page]]);
$formatter = new ResponseFormatter();
return $formatter->formatResponse("", $dataProvider->getTotalCount(), $dataProvider->getModels());
but it is throwing an exception
"message": "Setting unknown property: common\\models\\Item::name",
Here is the item Model with all the fields and relation.
<?php
namespace common\models;
use Yii;
use yii\behaviors\TimestampBehavior;
use yii\db\BaseActiveRecord;
use yii\db\Expression;
/**
* This is the model class for table "item".
*
* #property integer $id
* #property integer $subcategory_id
* #property string $title
* #property resource $description
* #property integer $created_by
* #property integer $updated_by
* #property string $created_at
* #property string $updated_at
* #property string $image
* #property integer $active
*
* #property SubCategory $subcategory
*/
class Item extends \yii\db\ActiveRecord
{
public $imageFile;
/**
* #inheritdoc
*/
public static function tableName()
{
return 'item';
}
/**
* #inheritdoc
*/
public function rules()
{
return [
[['created_by', 'updated_by'], 'required'],
[['subcategory_id', 'created_by', 'updated_by', 'active'], 'integer'],
[['description'], 'string'],
[['created_at', 'updated_at'], 'safe'],
[['title', 'image'], 'string', 'max' => 999],
[['title'], 'unique'],
[['imageFile'], 'file', 'skipOnEmpty' => true, 'extensions' => 'png, jpg'],
];
}
/**
* #inheritdoc
*/
public function attributeLabels()
{
return [
'id' => 'ID',
'subcategory_id' => 'Subcategory ID',
'title' => 'Title',
'description' => 'Description',
'created_by' => 'Created By',
'updated_by' => 'Updated By',
'created_at' => 'Created At',
'updated_at' => 'Updated At',
'image' => 'Image',
'active' => 'Active',
'imageFile' => 'Image',
];
}
/**
* #return \yii\db\ActiveQuery
*/
public function getSubcategory()
{
return $this->hasOne(SubCategory::className(), ['id' => 'subcategory_id']);
}
/**
* #return \yii\db\ActiveQuery
*/
public function getCreatedBy()
{
return $this->hasOne(User::className(), ['id' => 'created_by']);
}
/**
* #return \yii\db\ActiveQuery
*/
public function getUpdatedBy()
{
return $this->hasOne(User::className(), ['id' => 'updated_by']);
}
public function behaviors()
{
return [
'timestamp' => [
'class' => TimestampBehavior::className(),
'attributes' => [
BaseActiveRecord::EVENT_BEFORE_INSERT => ['created_at', 'updated_at'],
BaseActiveRecord::EVENT_BEFORE_UPDATE => 'updated_at',
],
'value' => new Expression('NOW()'),
],
];
}
}

Answer 1

The joinWith makes a query using the joins requested, but result data are mapped in source model (in this case Item).
Since you have select(['item.*', 'sub_category.name']) , the framework will try to fill 'name' field of Item model, that does not exist and this generates the error.
According with documentation (http://www.yiiframework.com/doc-2.0/guide-rest-resources.html#overriding-extra-fields) you should have db relation subcategory populated from db, by default, but I don't see subcategory relation in your model.
So you have only to create subcategory relation in your model, such as:
public function getSubcategory() { return $this->hasOne(Subcategory::className(), ['id' => 'subcategory_id']); }
So you should solve your problem.
Other solution to have custom fields from more models could be:
1) Create a sql View (and from that create the Model) with fields that you want and pass it to ActiveDataProvide
2) Override extraFields method of the model (http://www.yiiframework.com/doc-2.0/yii-base-arrayabletrait.html#extraFields%28%29-detail)
Again, I suggest you to read this good article:
http://www.yiiframework.com/wiki/834/relational-query-eager-loading-in-yii-2-0/