Database relation with Laravel Eloquent ORM - laravel

I'm new to Laravel and I'm stuck. This is what I am struggling with:
$questions = Question::find($id)->quiz(); // this code retrieves data from
// the table using the primary key
// in the table. The is a parameter
// that is passed via get.
This is what I have right now:
$questions = Question::where('quiz_id', '=', $id)->quiz();
This is the error I get:
Call to undefined method Illuminate\Database\Query\Builder::quiz()
What I want to do:
I want to run a query to get data from my database table using the foreign key in the table not the primary key, I also want to be able to use relations with this as seen from what I tried to do above.
Edit: Added the Question Model
<?php
class Question extends Eloquent{
protected $table = 'quiz_questions';
public function quiz()
{
return $this->belongsTo('Quiz');
}
}

Calling the quiz() function from Question::find($id)->quiz() will return a Query Builder instance allowing you to query the parent of the Question, its not going to return any data at that point until you call ->get() or another method that actually executes the query.
If you're wanting to return all the questions belonging to a certain quiz then you can do it like this.
$questions = Question::where('quiz_id', $id)->get();
This will return an Eloquent\Collection of the results for all questions with a quiz_id that is equal to $id.
If you've setup the relations between the Quiz and Questions then you can also do this using the Laravel relations.
$quiz = Quiz::findOrFail($id);
foreach($quiz->questions as $question)
{
// Do stuff with $question
}
Laravel will automagically pull Questions from the database that belongTo the Quiz you've already got from the database, this is known as eager loading http://laravel.com/docs/4.2/eloquent#eager-loading

Wader is correct, just calling where() will not execute your query. You either call get() and get an iterable result or use first() if you only want one result.
$quiz = Question::where('quiz_id', '=', $id)->first()->quiz();

Related

Get data from another model

$objects = Objects::where("id_host", $hostId)
->orderBy("id", "desc")
->get();
In the collection , each object has a type_id field . How can I use this field to get a record in another model and mix them into this object in the response
First thing is first, in order to show the relationship between the records, you'll need to set up a One-to-Many/Many-to-One relationship. This allows you to readily call those relationships from within Laravel and to load them together.
Without being able to see your Type and Object classes, I really can't give specific advice on this, but it should look something like this:
Objects
public function type(): BelongsTo
{
return $this->belongsTo(Type::class);
}
Type
public function objects(): HasMany
{
return $this->hasMany(Objects::class);
}
Once you've done that, you can add a with(...) call to your Eloquent query to eager load the relationship.
$objects = Objects::where("id_host", $hostId)
->orderBy("id", "desc")
->with('type')
->get();
Alternatively, if you don't want to eager load it for some reason, you can call $object->type to get the Type object.

Laravel eloquent for four tables

I'm new to Laravel. I am developing a project. and in this project I have 4 tables related to each other
-Users
-Orders
-OrderParcels
-Situations
When listing the parcels of an order, I want to get the information of that order only once, the user information of that order once again, and list the parcels as a table under it. so far everything ok. but I also want to display the status of the parcels listed in the table as names. I couldn't add the 4th table to the query. do you have a suggestion? I'm putting pictures that explain the structure below.
My current working code is
$orderParcels = Orders::whereId($id)
->with('parcels')
->with('users:id,name')
->first();
and my 'orders' model has method
public function parcels(){
return $this->hasMany(OrderParcels::class);
}
public function users(){
return $this->hasOne(User::class,'id','affixer_id');
}
Note[edit]: I already know how to connect like this
$orderParcels = DB::table('order_parcels as op')
->leftjoin('orders as o','op.orders_id','o.id')
->leftjoin('users as u','o.affixer_id','u.id')
->leftjoin('situations as s','op.status','s.id')
->select('op.*','o.*','u.name','s.situations_name')
->where('op.orders_id',$id)->get();
but this is not working for me, for each parcels record it returns me orders and user info. I want once orders info and once user info.
Laravel provides an elegant way to manage relations between models. In your situation, the first step is to create all relations described in your schema :
1. Model Order
class User extends Model {
public function parcels()
{
return $this->hasMany(OrderParcels::class);
}
public function users()
{
return $this->hasOne(User::class,'id','affixer_id');
}
}
2. Model Parcel
class Parcel extends Model {
public function situations()
{
return $this->hasOne(Situation::class, ...);
}
}
Then, you can retrieve all desired informations simply like this :
// Retrieve all users of an order
$users = $order->users; // You get a Collection of User instances
// Retrieve all parcels of an order
$parcels = $order->parcels; // You get a Collection of User instances
// Retrieve the situation for a parcel
$situations = $parcel->situations // You get Situation instance
How it works ?
When you add a relation on your model, you can retrieve the result of this relation by using the property with the same name of the method. Laravel will automatically provide you those properties ! (e.g: parcels() method in your Order Model will generate $order->parcels property.
To finish, in this situation where you have nested relations (as describe in your schema), you should use with() method of your model to eager load all the nested relation of order model like this :
$orders = Orders::with(['users', 'parcels', 'parcels.situations'])->find($id)
I encourage you to read those stubs of Laravel documentation :
Define model relations
Eager loading
Laravel Collection
Good luck !
Use join to make a perfect relations between tables.
$output = Orders::join('users', 'users.id', '=', 'orders.user_id')
->join('order_parcels', 'order_parcels.id', '=', 'orders.parcel_id')
->join('situations', 'situation.id', '=', 'order_parcels.situation_id')
->select([
'orders.id AS order_id',
'users.id AS user_id',
'order.parcels.id AS parcel_id',
'and so on'
])
->where('some row', '=', 'some row or variable')->get();

How to use where condition in laravel eloquent

I am using laravel eloquent. I have fetched data from two table using eloquent.
I have post table and chat table. For post table I have model Post.php and for chat table I have model Chat.php. Here is the the eloquent relation I have created to fetch chat for individual post for a user.
in Post.php
public function TeamMessage()
{
return $this->hasMany('App\Chat','post_id');
}
And in Chat.php
public function ChatRelation()
{
return $this->belongsTo('App\Post');
}
it is working perfect. But this relation fetch all messages for a specific post. I want to fetch all unread message from chat table. I have a column named unread in chat table.
Now my question is how I can fetch only unread message for a specific post.
While the other answers all work, they either depend on scopes (which are very useful in many circumstances) or on you having already instantiated an instance of $post, which doesn't let you eager load multiple posts with their messages.
The dynamic solution is this, which will let you fetch either 1 or more posts and eager load their messages with subquery:
$posts = Post::with(['TeamMessage' => function ($query) {
$query->where('unread', true); // This part applies to the TeamMessage query
}])->get();
See in documentation
Edit:
If you, however, want to filter the posts, to only show those that have unread messages, you need to use whereHas instead of with:
$posts = Post::whereHas(['TeamMessage' => function ($query) {
$query->where('unread', true); // This part applies to the TeamMessage query
}])->get();
More in the documentation.
You can also chain whereHas(...) with with(...).
For querying relationships, you have to call them as functions instead of properties, like this:
$unreadPosts = $post->TeamMessage()->where('unread', true)->get();
For more information on this you can take a look at the docs.
You need to create a local scope on your model, information on local scopes can be found here: https://laravel.com/docs/5.6/eloquent#local-scopes
public function scopeUnread($query)
{
return $query->where('unread', 1);
}
Then in your controller/view
$unread = $yourmodel->unread()
First I would change your relation names to the name of the entity in lower case:
in Post.php
public function chats()
{
return $this->hasMany('App\Chat','post_id');
}
And in Chat.php
public function post()
{
return $this->belongsTo('App\Post');
}
public function scopeUnread($query)
{
return $query->where('unread', 1);
}
Then you can use
$post->chats()->unread()->get();

Laravel 5.2 How to get all user which contains permission Many to Many

I have table with many to many relationship.
User many to many Permission
I already define many to many relationship on both model, and create the pivot table also.
What I want is get all user which contain permission name
What I have done so far is
User::all()->permissions->contains('name', 'access.backend.admin')->get();
But it give me
Undefined property: Illuminate\Database\Eloquent\Collection::$permissions on line 1
What wrong with my code?
User::All() returns a collection not model object. You have iterate over the collection to get the model object and use ->permissions().
For exapmle:
$users = User::all();
foreach ($users as $user) {
$user->permissions->contains('name', 'access.backend.admin'); // returns boolean
}
Or you can get a single model from DB as:
$user = User::first();
$user->permissions->contains('name', 'access.backend.admin'); // returns boolean
Update 1
To get users which contain desired permission use filter() method as:
$filtered_users = $users->filter(function ($user) {
if ($user->permissions->contains('name', 'access.backend.admin')) {
return $user;
}
});
Update 2
You can also write a query which returns the desired result as:
$filtered_users = User::whereHas('permissions', function($q) {
$q->where('name', 'access.backend.admin');
})->get()
I have a similar case of questions and tags, they have many to many relationship.
So when i have to fetch all question with a particular tag then i do this
$tag = Tag::where('name','laravel')->get()->first();
I first retrieved the Tag model with name laravel.
and then retrieved all questions having tag laravel.
$questions = $tag->questions;
Similarly you can do this
$permission = Permission::where('name','access.backend.admin')->get()->first();
$users = $permission->users;

Using find() in Laravel to retrieve a database object

I am working through the Laravel 4 From Scratch tutorial at https://laracasts.com/series/laravel-from-scratch. Tutorial 4: Database Access describes several methods for retrieving data from a database.
One in particular I cannot get to work:
In my routes.php, I have
Route::get('/', function()
{
$bottle = DB::table('bottle')->find(1);
dd($bottle);
});
The only output is the "Whoops, looks like something went wrong." page. In the bottle table of my database, the primary key has the name bottle_ID. I would guess this has something to do with the problem, but I cannot find any information on how to change the find() parameter. So how do I use 'find' to return an object from my database?
The following code does work:
// returns everything from bottle table
$bottles = DB::table('brewery')->get();
return $bottles;
// returns all data for the bottle with an ID of 10
$bottle = DB::table('bottle')->where('bottle_ID', '=', 10)->get();
return $bottle;
// returns all ales from the database
$bottles = DB::table('bottle')->where('beer_type', '=', 'Ale')->get();
return $bottles;
When used in the query builder (DB::table()...) the find() method has the primary key column hardcoded as id:
public function find($id, $columns = array('*'))
{
return $this->where('id', '=', $id)->first($columns);
}
What you should do instead is use where() and first():
$bottle = DB::table('bottle')->where('bottle_ID', 1)->first();
Or if you decide to use Eloquent Models you can specify the key column name:
class Bottle extends Eloquent {
protected $primaryKey = 'bottle_ID';
}
And retrieve the model like this:
$bottle = Bottle::find(1);

Resources