How to show relational data in yii2 - php

Question

I'm having trouble understanding how relations work in yii 2
I have 2 tables in a mysql database, author and book.
book has a column named author which links to the id of the author table via foreign key.
I've generated CRUD using gii, and I want the author name to appear in the list view, as well as dropdowns for the author name in the create and update views.
But I cant seem to get the relation working even in the list view.
Here's my code
Book Model:
<?php
namespace app\models;
use Yii;
use app\models\Author;
/**
* This is the model class for table "book".
*
* #property integer $id
* #property string $name
* #property integer $author
*/
class Book extends \yii\db\ActiveRecord
{
/**
* #inheritdoc
*/
public static function tableName()
{
return 'book';
}
/**
* #inheritdoc
*/
public function rules()
{
return [
[['name', 'author'], 'required'],
[['author'], 'integer'],
[['name'], 'string', 'max' => 11]
];
}
/**
* #inheritdoc
*/
public function attributeLabels()
{
return [
'id' => 'ID',
'name' => 'Name',
'author' => 'Author',
];
}
public function getAuthor()
{
return $this->hasOne(Author::className(), ['id' => 'author']);
}
}
BookSearch Model:
<?php
namespace app\models;
use Yii;
use yii\base\Model;
use yii\data\ActiveDataProvider;
use app\models\Book;
/**
* BookSearch represents the model behind the search form about `app\models\Book`.
*/
class BookSearch extends Book
{
/**
* #inheritdoc
*/
public function rules()
{
return [
[['id', 'author'], 'integer'],
[['name'], 'safe'],
];
}
/**
* #inheritdoc
*/
public function scenarios()
{
// bypass scenarios() implementation in the parent class
return Model::scenarios();
}
/**
* Creates data provider instance with search query applied
*
* #param array $params
*
* #return ActiveDataProvider
*/
public function search($params)
{
$query = Book::find();
$query->joinWith('author');
$dataProvider = new ActiveDataProvider([
'query' => $query,
]);
var_dump($dataProvider);
if (!$this->validate()) {
// uncomment the following line if you do not want to return any records when validation fails
// $query->where('0=1');
return $dataProvider;
}
$query->andFilterWhere([
'id' => $this->id,
'author' => $this->author,
]);
$query->andFilterWhere(['like', 'name', $this->name]);
return $dataProvider;
}
}
Also, here's the view file:
<?php
use yii\helpers\Html;
use yii\grid\GridView;
/* #var $this yii\web\View */
/* #var $searchModel app\models\BookSearch */
/* #var $dataProvider yii\data\ActiveDataProvider */
$this->title = 'Books';
$this->params['breadcrumbs'][] = $this->title;
?>
<div class="book-index">
<h1><?= Html::encode($this->title) ?></h1>
<?php // echo $this->render('_search', ['model' => $searchModel]); ?>
<p>
<?= Html::a('Create Book', ['create'], ['class' => 'btn btn-success']) ?>
</p>
<?= GridView::widget([
'dataProvider' => $dataProvider,
'filterModel' => $searchModel,
'columns' => [
['class' => 'yii\grid\SerialColumn'],
'id',
'name',
[
'attribute' => 'author',
'value' => 'author.name',
],
['class' => 'yii\grid\ActionColumn'],
],
]); ?>
</div>
Author Model:
<?php
namespace app\models;
use Yii;
/**
* This is the model class for table "author".
*
* #property integer $id
* #property string $name
*/
class Author extends \yii\db\ActiveRecord
{
/**
* #inheritdoc
*/
public static function tableName()
{
return 'author';
}
/**
* #inheritdoc
*/
public function rules()
{
return [
[['name'], 'required'],
[['name'], 'string', 'max' => 200]
];
}
/**
* #inheritdoc
*/
public function attributeLabels()
{
return [
'id' => 'ID',
'name' => 'Name',
];
}
}
I think I may have to change something somehwhere in the author/authorSearch model.
Can someone help
thanks

Answer 1

You can also add columns to a gridview with value from an anonymous function as described here http://www.yiiframework.com/doc-2.0/yii-grid-datacolumn.html#$value-detail. For example you can show an author's name like this in a gridview:
<?= GridView::widget([
'dataProvider'=>$dataProvider,
'filterModel'=>$searchModel,
'columns'=>[
[
'attribute'=>'author.name',
'value'=>function ($model, $key, $index, $column) {
return $model->author->name;
},
],
//...other columns
]);
?>
you can also return a html-link to the detail-view of an author like this:
//...
'columns'=>[
[
'attribute'=>'author',
'value'=>function ($model, $key, $index, $column) {
return Html::a($model->author->name, ['/author/view', 'id'=>$model->author->id]);
},
],
//...
],
//...

Answer 2

You can access relation table data in any crud view file using their relation name. $model->relName->attribute_name.
And You can access relation table data in gridview at following way :
<?= GridView::widget([
'dataProvider' => $dataProvider,
'filterModel' => $searchModel,
'columns' => [
[
'attribute' => 'author',
'value'=>'author.author_name', //relation name with their attribute
]
],
]);

Answer 3

First you need a get function in your model, but you have.
This is :
public function getAuthor()
{
return $this->hasOne(Author::className(), ['id' => 'author']);
}
Now you just need do one more thing.
Go to the index file, and to GridView, and columns.
Write this into columns:
[
'attribute' => 'author',
'value' => 'author.name',
],
In the value, the first parameter is your Get function, what named is : getAuthor, and . after your column name.

Answer 4

Hello in your BookSearch Mode please add below code like this.
$query->joinWith(array('author'));
$query->andFilterWhere(['id' => $this->id,])
->andFilterWhere(['like', 'author.author_name', $this->author]);
And in your view file please use below given code below code is for view file inside grid attrubute.
[
'attribute' => 'author',
'value' => 'author.name',
]
i hope this will helps you. and i hope in author table name is stored in name column.

Answer 5

This worked for me - inside the BookSearch Model:
public function search($params)
{
$dataProvider = new \yii\data\SqlDataProvider([
'sql' => 'SELECT book.id as id ,book.author_fk, book.name as book_name , author.name as author_name' .
' FROM book ' .
'INNER JOIN author ON (book.author_fk = author.id) '
]);
$this->load($params);
if (!$this->validate()) {
// uncomment the following line if you do not want to return any records when validation fails
// $query->where('0=1');
return $dataProvider;
}
return $dataProvider;
}
Only issue now is getting the ActionColumn to work correctly, they're currently linking to the wrong IDs, help anyone.