I created 2 models, "Post" and "Category". This is a many to many relationship, works great.
My tables are the following :
alex_blog_posts : where posts are stored with columns like "title", "published" etc...
alex_blog_categories : where categories are stored with columns like "title", "parent_id" etc...
alex_blog_posts_categories : where the relation is stored between posts and categories with columns "post_id", "category_id"
Let's assume I want to filter all posts that are associated to a category with name : "Category 1"
public function scopeFilterCategory($query) {
$query->join(????); // My problem is to replace the ???
$query->where('title', '=', 'Category 1');
return $query;
}
I'm not familiar enought with october and laravel yet and I'm stuck here. Probably very simple for laravel expert but I need a concrete example of something working cause all things I tried failed :/
Thanks for your help
laravel have the "whereHas":
https://laravel.com/docs/5.5/eloquent-relationships#querying-relationship-existence
On the post model you need the write this query:
$posts = Post::whereHas($relationName, function ($query) {
$query->where('title', =, 'Category 1');
})->get();
$relationName - should be the name of the function that define the relation in your model (etc: 'categories')
For Laravel
There is a good answer on Laracasts
Scope for many to many relation
The following is an improved version.
Assume we have authors & articles many-to-many relation (with a pivot authors_articles);
Assume we have belongsToMany relation defined in both models;
// in Article model
public function scopeFromAuthor($query, $authorId)
{
return $query->whereHas('authors', function ($query) use ($authorId) {
$query->where('authors_articles.author_id', '$authorId');
});
}
Related
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();
I have 4 table categories, initiatives, a pivot table for the "Many To Many" relationship category_initiative and initiativegroup table related with initiatives table with initiatives.initiativesgroup_id with one to many relation.
With pure sql I retrive the information I need with:
SELECT categories.id, categories.description, initiatives.id, initiatives.description, initiativegroups.group
FROM categories
LEFT JOIN category_initiative ON categories.id = category_initiative.category_id
LEFT JOIN initiatives ON category_initiative.initiative_id = initiatives.id
LEFT JOIN initiativegroups ON initiatives.initiativegroup_id = initiativegroups.id
WHERE categories.id = '40'
How can I use eloquent model to achieve same results?
Since you have such a specific query touching multiple tables, one possibility is to use query builder. That would preserve the precision of the query, retrieving only the data you specifically need. That would look something like this:
$categories = DB::table('categories')
->select([
'categories.id',
'categories.description',
'initiatives.id',
'initiatives.description',
'initiativegroups.group',
])
->leftJoin('category_initiative', 'categories.id', '=', 'category_initiative.category_id')
->leftJoin('initiatives', 'category_initiative.initiative_id', '=', 'initiatives.id')
->leftJoin('initiativegroups', 'initiatives.initiativegroup_id', '=', 'initiativegroups.id')
->where('categories.id', '=', 40)
->get();
In your models define the relationships:
Category.php model
public function initiatives()
{
return $this->belongsToMany('App\Initiative');
}
Initiative.php model (If has many categories change to belongs to many)
public function category()
{
return $this->belongsTo('App\Category');
}
Then maybe change your initiativegroup -> groups table, and then create a pivot table called group_initiative. Create model for group. Group.php and define the relationship:
public function initiatives()
{
return $this->belongsToMany('App\Initiative');
}
Then you can also add the following relationship definition to the Initiative.php model
public function group()
{
return $this->belongsTo('App\Group');
}
That should get you started.
for the record..
with my original relationship, but changing table name as alex suggest, in my controller:
$inits = Category::with('initiative.group')->find($id_cat);
simple and clean
I am using laravel 5.6. I've two tables. One is Teachers(id,name,email,salary) another is Students(id,teacher_id,name,email) I have joined 2 tables
$vu_data = Teacher::join('Students', 'teachers.id', '=', 'students.teacher_id')
->where('teachers.id', $id)
->get();
return view('view_full')->with('vu_data',$vu_data);
view_full.blade.php
{{$vu_data[0]->name}}
How can I display sthdent name and teacher nam. There are same column name.
Thanks in advance
The better way is to use laravel Eloquent relationships https://laravel.com/docs/5.7/eloquent-relationships#one-to-many*.
Put on your Teachers model
public function students(){
return $this->hasMany('App\Students', 'teacher_id', 'id');
}
You will call like that:
$vu_data->students()
If you want to use yur select, simple use de 'AS'
->select('Teachers.name as teacher_name', 'Students.name as student_name')
You'll need to specify the columns in a select() clause on the query, and rename the columns. Such as
Teacher::join('Students', 'teachers.id', '=', 'students.teacher_id')
->where('teachers.id', $id)
->select('teachers.name AS teacher_name', 'students.name AS student_name', [ rest of columns])
->get();
However, you might want to look into Eloquent relationships, which will allow you to iterate through a teacher then all of that teacher's students, or vice versa.
You need to add before ->get()
->select('Teachers.name as teacherName', 'Students.name as studentName')
and than you can use
{{$vu_data[0]->teacherName}}
and
{{$vu_data[0]->studentName}}
As per your table structure one teacher has many students. Hence instead of using join you can use laravel relationships with hasMany :
Teacher has many students - Teacher Model :
public function students(){
return $this->hasMany(Students::class);
}
A student belongs to a teacher - Student Model :
public function teacher(){
return $this->belongsTo(Teacher::class);
}
Now you can get relationships like below :
Get all teachers with their students :
$teachers = Teacher::with('students')->get();
Get all students of a particular techer :
$teacher = Teacher::find($teacherId);
$students = $teacher->students;
Finally using this, you can convert this :
$vu_data = Teacher::join('Students', 'teachers.id', '=', 'students.teacher_id')
->where('teachers.id', $id)
->get();
return view('view_full')->with('vu_data',$vu_data);
To this :
$teacher = Teacher::find($id);
return view('view_full', compact('teacher'));
Then inside blade :
You can get teacher details : {{ $teacher->name }}
and students :
#if($teacher->students->count() > 0)
#foreach($teacher->students as $student)
{{ $student->name }}
#endforech
#endif
My database structure is the following:
So I've got a Bloggers table (sorry for the typo in the image), which has 3 topic fields, all 3 are foreign keys to the topics' table id.
I made a Blogger view front-end with a simple table showing all blogger columns. At the moment, the id's of the topics are being shown instead of the names though.
How can I change this?
I've already tried the following in my Controller, but that just creates duplicates in the view with different values in the main_topic column.
$bloggers= DB::table('bloggers')
->join('topics', function ($join) {
$join
->on('bloggers.main_topic', '=', 'topics.id')
->orOn('bloggers.subtopic1', '=', 'topics.id')
->orOn('bloggers.subtopic2', '=', 'topics.id');
})
->select('bloggers.*', 'topics.name as main_topic')
->get();
return view('pages.bloggers', compact('bloggers'));
The answer to my specific question was a little different from the answers given, so I'll post it here in case anyone needs it in the future.
So I've got 3 tables: bloggers, topics and a pivot table called blogger_topic. bloggers contains 3 foreign keys (integers) to topics called main_topic, subtopic1, subtopic2. The pivot table contains a blogger_id, and a topic_id.
What I ended up with:
Blogger.php model:
public function mainTopic()
{
return $this->belongsTo('App\Models\Topic', 'main_topic', 'id');
}
public function subtopicOne()
{
return $this->belongsTo('App\Models\Topic', 'subtopic1', 'id');
}
public function subtopicTwo()
{
return $this->belongsTo('App\Models\Topic', 'subtopic2', 'id');
}
Topic.php model:
public function bloggers()
{
return $this->belongsToMany('App\Models\Blogger');
}
View (blogger.blade.php):
#foreach($bloggers as $blogger)
{{ $blogger->mainTopic }}
{{ $blogger->subtopicOne }}
{{ $blogger->subtopicTwo }}
#endforeach
I think you should change your database tables if possible as below (sample link), by creating a pivot table. And then I think you should make relationships in Blogger and Topic model files with many-to-many. Then it would be very easy to fetch all related topics. For eg,
$topics = $blogger->topics;
Here you can reference the sample db table designs
I kindly recommend you to use models in Laravel coz they'll make your life more simple. Hope this help.
If you cant change your database, you could use group_concat on the results. Not sure if it will work but something like:
DB::table('bloggers')
->join('topics', function ($join) {
$join
->on('bloggers.main_topic', '=', 'topics.id')
->orOn('bloggers.subtopic1', '=', 'topics.id')
->orOn('bloggers.subtopic2', '=', 'topics.id');
})
->groupby('bloggers.id')
->select('bloggers.*', 'topics.name as main_topic', DB::raw('group_concat(topics.name)'))
->get();
I have the following code which works but doesn't seem to follow the laravel eloquent way:
Article::left_join('images', 'articles.id', '=', 'images.article_id')
->join('article_category', 'articles.id', '=', 'article_category.article_id')
->where('article_category.category_id', '=', $category_id)
->get();
I have 4 tables; articles and categories which have a many to many relationship with each other, a pivot table article_category table which holds the article id and category id and an image table which has one to one relationship with an article.
I setup my models as:
class Category extends Eloquent {
public static function get_articles($category_id) {
return static::find($category_id)->has_many_and_belongs_to('Article');
}
class Article extends Eloquent {
public function categories() {
return $this->has_many_and_belongs_to('Category');
}
public function image() {
return $this->has_one('Image');
}
However I can't seem to get all three bits of info together. I can do:
Category::get_articles($current_category)->get();
To get all articles in a given category but I can't seem to get the image for the article, there seems to be nothing I can chain onto? Unless I'm doing it incorrectly? Is there a trick I'm missing?
I even tried the stripped down version from the docs:
foreach (Article::with('image')->get() as $article) {
echo $article->image->foo;
}
However I get an error: Trying to get property of non-object, even though var_dump shows $article->image is an object! Weird.
Thanks
If you have not setup a model for the image table, do that. The ORM needs the model there so it knows what 'Image' refers to.
Can you get the category information using the ::with method or is that troublesome too?