I have related tables (table train_schedule have departute_station_id and arrival_station_id) linked on Station:
enter image description here
I want select records from train_schedule with stations name:
$trainsTchedule = TrainSchedule::find()
->joinWith('getArrivalStation')
->joinWith('getDepartuteStation()')
->all();
In TrainSchedule class:
/**
* #return \yii\db\ActiveQuery
*/
public function getArrivalStation()
{
return $this->hasOne(Station::className(), ['id' => 'arrival_station_id']);
}
And
/**
* #return \yii\db\ActiveQuery
*/
public function getDepartuteStation()
{
return $this->hasOne(Station::className(), ['id' => 'departute_station_id']);
}
Error:
Relation names are case sensitive. app\models\TrainSchedule has a
relation named "arrivalStation" instead of "ArrivalStation".
Howe get data wrom linked tables?
You have defined your relations correctly but, you are calling them incorrectly. Your relation
getArrivalStation should be specified as arrivalStation
getDepartuteStation() should be departuteStation
when specifying in the joinWith, and you need to provide an array if you need to specify multiple relations when calling joinWith as currently your second call ->joinWith('getDepartuteStation()') is overriding the previous one ->joinWith('getArrivalStation').
So the query should look like below
$trainsTchedule = TrainSchedule::find()
->joinWith(['arrivalStation','departuteStation'])
->all();
You should read about Working with Relational Data
Related
I have 2 tables in the db (mysql), and between the 2 there is no classic relationship through keys or ids. The only way I could define relationship would be through attribute values. E.g. table wheel and car and certain wheels would match certain cars because of the size only. Can it be defined on DB level, and/or in yii2, and if yes, how?
In the relations I can add an onCondition(), but you have to define an attribute (???), too:
public function getWheels() {
return $this->hasMany(\app\models\Wheel::className(), ['???' => '???'])->onCondition(['<', 'wheelsize', $this->wheelsize]);
}
I could use a fake attribute and set it in all records like to 1, but it seems a little bit odd for me.
I find nothing on the web regarding this or maybe I'm just searching the wrong way, or maybe I'm trying something that's totally bad practice. Can you please point me to the right direction?
Hypothetically you can set an empty array as a link, but for security reasons (I think) the condition "0 = 1" is automatically added in the select.
I faced your own problem several times and the best solution I could find was to use ActiveQuery explicitly (similar to what happens for hasOne and hasMany):
public function getWheels() {
return new ActiveQuery(\app\models\Wheel::className(), [
'where' => 'my condition' // <--- inserte here your condition as string or array
'multiple' => true // true=hasMany, false=hasOne
// you can also add other configuration params (select, on condition, order by, ...
]);
}
This way you can get both the array and the ActiveQuery to add other conditions:
var_dump($model->wheels); // array of wheels objects
var_dump($model->getWheels()); // yii\db\ActiveQuery object
$model->getWheels()->andWhere(...); // customize active query
I don't think that you could achieve this through relation.
But there is a way to work around the limitation.
<?php
namespace app\models;
class Car extend \yii\db\ActiveRecord
{
/**
* #var \app\models\Wheel
*/
private $_wheels;
/**
* #return \app\models\Wheel[]
*/
public function getWheels()
{
if (!$this->_wheels) {
$this->_wheels = Wheel::find()
->where(['<', 'wheelsize', $this->wheelsize])
//->andWhere() customize your where here
->all();
}
return $this->_wheels;
}
}
Then you could access the wheels attribute just as relation does.
<?php
$car = Car::find(1);
$car->wheels;
Beware that this way does not support Eager Loading
I have been struggling with this for quite a while. I use PyroCMS and it has a Posts module that has all the fields in the database and all that and if you want to find a specific post, you can just use a normal WHERE clause and find a post by a date and so on.
But if a field is checked in CMS as translatable, I can't access that field and use it to find a post, because the CMS creates another field in another table that is called posts_translations, and it contains all the fields that are translatable. Usually that is a simple $posts->where("field","value"), but the field doesn't exist if it's translatable.
So I tried to use whereHas, but it doesn't really return anything.
public function meklet(PostRepositoryInterface $posts, $q)
{
$postss = $posts->all()->whereHas('translations', function($query) use($q) {
$query = $query->where(function($query) use($q) {
$query->where('title', 'like', '%'.$q.'%');
});
});
die(var_dump($q));
return $this->view->make("mendo.module.report::reports/search");
}
As you can see I use PostRepositoryInterface maybe I need to use some other class to access what I want? Im very confused, I know its a laravel base, but I can't really wrap my head around this simple problem.
You shouldn't use one letter variables and too much nested functions there:
/**
* Searches for all matches.
*
* #param PostRepositoryInterface $posts The posts
* #param string $search The search
* #return View
*/
public function search(PostRepositoryInterface $posts, $search)
{
/* #var PostCollection $results */
$results = $posts->all()->filter(
function (PostInterface $post) use ($search) {
return str_contains(
strtolower($post->getFieldValue('title')),
strtolower($search)
);
}
);
dd($results);
return $this->view->make('mendo.module.report::reports/search', [
'posts' => $results,
]);
}
And route should be like:
'posts/search/{search}' => [
'as' => 'anomaly.module.posts::posts.search',
'uses' => 'Anomaly\PostsModule\Http\Controller\PostsController#search',
],
To use a DB query directly you need to write translations join self. It is not so difficult.
I want to receive data like this:
categories
----category1
----category2
topProducts
----product1
--------photo1
--------photo2
----product2
--------photo1
--------photo2
I need get all categories and top x products.
Each product has two photos.
How can i do this by using yii2 restful?
Thanks.
the query shold look something like this
Category::find()
->with(['subcategories','topProducts', 'topProducts.images'])
->all();
you can use joinWith if you absolutely want a single query
if you retrieve your data with an ActiveController, you need to specify extraFields to the Category model. (here's a rest-specific usage example - rest of the guide should prove usefull as well)
Category model:
public function extraFields() {
return ['subcategories', 'topProducts'];
}
// product relation
public function getTopProducts(){
return $this->hasMany(Product::className(), ['category_id' => 'id'])
// ->order()->where() // your criterias
->limit(10);
}
// subcategories
public function getChildren(){
return $this->hasMany(Category::className(), ['id' => 'parent_id']);
}
Product model:
public function extraFields() {
return ['iamges'];
}
public function getImages(){
return $this->hasMany(Image::className(), ['product_id' => 'id'])
}
ps. since you haven't posed any code or table structure, all relations in my example are based on standard naiming convention
I have the following tables:
content - id (PK), title, ... other fields ...
content_category - content_id (FK to content), category_id (FK to content)
Where a piece of content has_many categories, and a category is also a piece of content.
In content I have the following code:
public function getCategories()
{
return $this
->hasMany(Category::className(), ['id' => 'category_id'])
->viaTable('content_category', ['content_id' => 'id']);
}
public function getCategoriesCsv(){
...
}
For my grid view in the backend, I'd like to display a comma separated list of categories for each piece of content.
I'm aware that I could select this information separately, but I would like to do it as part of the find query and using the existing relation if possible.
Using defined relation (more simple, less efficient).
This approach typical way and it works with related Category models. Therefore it requires a lot of memory.
class Content extends \yii\db\ActiveRecord
{
/**
* Returns comma separated list of category titles using specified separator.
*
* #param string $separator
*
* #return string
*/
public function getCategoriesCsv($separator = ', ')
{
$titles = \yii\helpers\ArrayHelper::getColumn($this->categories, 'title');
return implode($separator, $titles);
}
// ...
}
Should be used with eager loading:
Content::find()
->with('categories')
->all();
Using subquery (more efficient, less convenient)
This approach uses subqueries and don't use relations and related models. Therefore this way more fast and keeps a lot of memory.
class Content extends \yii\db\ActiveRecord
{
const ATTR_CATEGORIES_CSV = 'categoriesCsv';
/**
* #var string Comma separated list of category titles.
*/
public $categoriesCsv;
/**
* Returns DB expression for retrieving related category titles.
*
* #return \yii\db\Expression
*/
public function prepareRelatedCategoriesExpression()
{
// Build subquery that selects all category records related with current content row.
$queryRelatedCategories = Category::find()
->leftJoin('{{%content_category}}', '{{%content_category}}.[[category_id]] = {{%category}}.[[id]]')
->andWhere(new \yii\db\Expression('{{%content_category}}.[[content_id]] = {{%content}}.[[id]]'));
// Prepare subquery for retrieving only comma-separated titles
$queryRelatedCategories
->select(new \yii\db\Expression('GROUP_CONCAT( {{%category}}.[[title]] )'));
// Prepare expression with scalar value from subquery
$sqlRelatedCategories = $queryRelatedCategories->createCommand()->getRawSql();
return new \yii\db\Expression('(' . $sqlRelatedCategories . ')');
}
// ...
}
When alias of additional column equals to some model property, it will be populated by all() method:
$contentModels = Content::find()
->andSelect([
'*',
Content::ATTR_CATEGORIES_CSV => Content::prepareRelatedCategoriesExpression(),
])
->all();
foreach ($contentModels as $contentModel) {
$contentModel->id;
$contentModel->categoriesCsv; // it will be also populated by ->all() method.
// ...
}
ps: I not tested this code, probably should be fixed query for retrieving categories.
Moreover, in this example it written using base simple syntax, but it may be optimized to more cute state using various helpers, junction models etc.
WITH CATEGORIES LOADED
Originally I implemented it as:
public function getCategoriesCsv(){
$categoryTitles = [];
foreach ($this->categories as $category){
$categoryTitles[] = $category->title;
}
return implode(', ', $categoryTitles);
}
Thanks to #IStranger, I neatened this to:
public function getCategoriesCsv()
{
$titles = ArrayHelper::getColumn($this->categories, 'title');
return implode(', ', $titles);
}
WITHOUT CATEGORIES LOADED
I have now managed to avoid loading all the category models by adding a separate CategoryCsv ActiveRecord:
class CategoryCsv extends ActiveRecord
{
public static function tableName(){
return '{{%content_category}}';
}
public function attributes(){
return ['content_id', 'value'];
}
public static function find(){
return parent::find()
->select([
'content_id',
'GROUP_CONCAT(
categoryCsv.title
ORDER BY categoryCsv.title
SEPARATOR ", "
) value'
])
->innerJoin('content categoryCsv','category_id = categoryCsv.id')
->groupBy('content_id');
}
}
Then in the Content ActiveRecord:
public function getCategoriesCsv(){
return $this->hasOne(CategoryCsv::className(), ['content_id' => 'id']);
}
Thus I can access the value like so:
$contents = Content::find()->with('categoryCsv')->all();
foreach($contents as $content){
echo $content->categoryCsv->value;
}
I am dealing with the following situation: I have two models, an Employee with id and name fields and a Telephone with id, employee_id and flag fields. There is also an one-to-many relationship between these two models, that is an employee may have many telephones and a telephone may belong to a single employee.
class Employee extends Model
{
public function telephones()
{
return $this->hasMany(Telephone::class);
}
}
class Telephone extends Model
{
public function employee()
{
return $this->belongsTo(Employee::class);
}
}
The Employee model references a table employees that exists in database schema named mydb1, while the Telephone model is related to a telephones table that exists in a different database schema named mydb2.
What I want is to fetch only the employees with at least one telephone of a specific flag eager loaded, using Eloquent and (if possible) not the query builder
What I tried so far without success is:
1) use the whereHas method in the Controller
$employees = Employee::whereHas('telephones', function ($query) {
$query->where('flag', 1); //Fetch only the employees with telephones of flag=1
})->with([
'telephones' => function ($query) { //Eager load only the telephones of flag=1
$query->where('flag', 1);
}
])->get();
What I try to do here is first to retrieve only the employees that have telephones with flag=1 and second to eager load only these telephones, but I get the following query exception because of the different db connections used:
Base table or view not found: Table mydb1.telephones doesn't exist (this is true, telephones exists in mydb2)
2) Eager load with constrains in the Controller
$employees = Employee::with([
'telephones' => function ($query) {
$query->where('flag', 1);
},
])->get();
This method eager loads the telephones with flag=1, but it returns all the employee instances, which is not what I really want. I would like to have a collection of only the employee models that have telephones with flag = 1, excluding the models with telephones = []
Taking into account this post, this post and #Giedrius Kiršys answer below, I finally came up with a solution that fits my needs, using the following steps:
create a method that returns a Relation object in the Model
eager load this new relationship in the Controller
filtered out the telephones of flag != 1 using a query scope in the Model
In Employee model
/**
* This is the new relationship
*
*/
public function flaggedTelephones()
{
return $this->telephones()
->where('flag', 1); //this will return a relation object
}
/**
* This is the query scope that filters the flagged telephones
*
* This is the raw query performed:
* select * from mydb1.employees where exists (
* select * from mydb2.telephones
* where telephones.employee_id = employee.id
* and flag = 1);
*
*/
public function scopeHasFlaggedTelephones($query, $id)
{
return $query->whereExists(function ($query) use ($id) {
$query->select(DB::raw('*'))
->from('mydb2.telephones')
->where('telephones.flag', $flag)
->whereRaw('telephones.employee_id = employees.id');
});
}
In the Controller
Now I may use this elegant syntax a’la Eloquent
$employees = Employee::with('flaggedTelephones')->hasFlaggedTelephones()->get();
which reads like "Fetch all the employees with flagged telephones eager loaded, and then take only the employees that have at least one flagged telephone"
EDIT:
After dealing with the Laravel framework for a while (current version used 5.2.39), I figured, that in fact, whereHas() clauses do work in case of the relationship model exists in a different database using the from() method, as it is depicted below:
$employees = Employee::whereHas('telephones', function($query){
$query->from('mydb2.telephones')->where('flag', 1);
})->get();
#Rob Contreras credits for stating the use of the from() method, however it looks like the method requires to take both the database and the table as an argument.
Not sure if this will work but you can use the from method to specify your database connection within the closure:
$employees = Employee::whereHas('telephones', function($query){
$query->from('mydb2')->where('flag', 1);
})->get();
Hope this helps
Dirty solution:
Use whereExists and scope for better readability.
In Your Employee model put:
public function scopeFlags($query, $flag)
{
$query->whereExists(function ($q) use ($flag) {
$q->select(\DB::raw(1))
->from('mydb2.telephones')
->where('telephones.flag', $flag)
->whereRaw('telephones.employee_id = employees.id');
});
}
Then modify your query like so:
$employees = Employee::flags(1)->get();