I have a project with the classes Semester, Course, and Assignment.
I wanted to get only Semesters that had at least one Course associated with it, so I did this:
Semester::has('courses', '>', '0')->get();
Now, I want get Semesters that have at least one Course that has at least one Assignment associated with it.
In the Semester class, I have a hasMany relationship with Course, and in Course, I have a hasMany relationship with Assignments. I also have a belongsTo for Assignment to Course and Course to Semester.
I have tried looking up closures, but none of the tutorials seem to relate to checking a collection of a collection. How would I run this code?
EDIT
After reading and testing more, I found that this code works:
Semester::whereHas('courses', function ($query) {
$query->has('assignments', '>', '0')
})->get();
huuuk's answer is a different approach but equally valid and helpful.
First of all define hasManyThrough relation in Semetster class
public function assignments()
{
return $this->hasManyThrough('App\Course', 'App\Assignment');
}
then you can reach your goal like so
Semester::has('assignments', '>=', '1')->get();
Related
Current relationships:
A Clinic hasMany Consultants
A Consultant belongsToMany Treatments (pivot table relationship)
A clinic may not have consultants, and a consultant may not have treatments. I only want to return clinics that has consultants, which has treatments, that includes a treatment that matches $treatment_id (hence the has existence check).
Current attempt (which returns 0 results):
clinic::whereHas('consultants.treatments', function ($query) use ($treatment_id) {
$query->where('treatment_id', $treatment_id);
})
->paginate(10);
I feel I require a whereHas within the whereHas function, to firstly determine if a consultant has treatments, but, if this logic is correct, how can I approach it within the function.
I am expecting 3 results to be returned, but currently it is 0.
How can I achieve this? Many thanks,.
Since it's many to many, it should be:
Clinic::whereHas('consultants.treatments', function ($query) use ($treatment_id) {
$query->where('id', $treatment_id);
})
->paginate(10);
I have a Laravel 4.2 site with a pretty simple database layout. The important part is a People model and a Subject model that have a many-to-many relationship. This works, so that, for instance:
$id = 5;
$ppl = Subject::find($id)->people()->orderBy('lastname')->get();
Returns all People for a given Subject. What I'm trying to do is instead of finding all the People for a single subject, to find all the people for multiple subjects. My guess was something like this:
$subjects = array(5, 6, 7);
$ppl = Subject::whereIn('id', $subjects)->people()->orderBy('lastname')->get();
That doesn't work (undefined method people()). Neither does the following (undefined property people):
$ppl = Subject::whereIn('id', $subjects)->people->orderBy('lastname')->get();
I'm currently just using raw SQL t get around this. How can I use eloquent relationships with where() or whereIn() calls on a model? Or, is there just a better eloquent way of approaching this problem.
Edit: Here's the raw SQL I used to get a list of the people.id's for a given array of subjects:
SELECT
DISTINCT(people.id)
FROM people
LEFT JOIN person_subject ON person_subject.person_id=people.id
WHERE
person_subject.subject_id IN (%s) AND
deleted_at IS NULL
Your eloquent relationships should allow you to eagar load the people related to a subject, you can do something like this:
Subject::whereIn('id', $subjects)->with('people')->orderBy('lastname')->get();
This will return your people related to the subjects.
Let me know if this doesn't work.
What you need is to join the tables to order by the lastname:
$ppl = Subject::whereIn('id', $subjects)
->select('subjects.*')
->distinct()
->join('people', 'people.id', '=', 'subjects.people_id')
->orderBy('lastname')
->get();
Check all your tables names because I don't know them and above are just an example one.
In Laravel 4.2 I have a model called Product with many-to-many relationshis to other models like Country or Category. I want to filter out products that are "incomplete", which means they have no connected countries or no connected categories. I can use whereDoesntHave() method to filter out one relation. When I use it two times in one query it creates AND condition, but I need OR. I can't find orWhereDoesntHave() method in API documentation. I can't pass multiple relations as arguments because it expects first argument to be a string.
I need something like this:
$products = Product::whereDoesntHave('categories')->orWhereDoesntHave('countries')->get();
Is there any way to achive whereDoesntHave() with multiple OR conditions?
You can use doesntHave and specify the boolean operator:
$products = Product::doesntHave('categories')->doesntHave('countries', 'or')->get();
Actually you only need whereDoesntHave if you want to pass in a closure to filter the related models before checking if any of them exist. In case you want to do that you can pass the closure as third argument:
$products = Product::doesntHave('categories', 'or', function($q){
$q->where('active', false);
})->doesntHave('countries', 'or')->get();
Since Laravel 5.5 there is an orWhereDoesntHave function.
You may use it like this
Product::whereDoesntHave('categories', function($q){ //... })
->orWhereDoesntHave('countries', function($q){//...})
->get();
From you example it seems that you are not using a where clause, so you may just use
Product::doesntHave('categories')
->orDoesntHave('countries')
->get();
Use
Product::whereDoesntHave('categories')->doesntHave('countries', 'or')->get();
Laravel Source Code:
whereDoesntHave https://github.com/illuminate/database/blob/master/Eloquent/Builder.php#L654
calls
https://github.com/illuminate/database/blob/master/Eloquent/Builder.php#L628
internally.
Let’s say we have Authors and Books, with 1-n relationship – one Author can have one or many Books. Here’s how it looks in app\Author.php:
public function books()
{
return $this->hasMany(\App\Book::class, 'author_id');
}
Now, what if we want to show only those Authors that have at least one book? Simple, there’s method has():
$authors = Author::has('books')->get();
Similarly, there’s an opposite method – what if we want to query only the authors without any books? Use doesnthave():
$authors = Author::doesnthave('books')->get();
It’s not only convenient, but also super-easy to read and understand, even if you’re not a Laravel developer, right?
What is the difference between the two methods where() and whereHas()? They both seem to be quite similar in the laravel documentation.
The method where() behaves like a regular SQL WHERE query part.
The method has() uses foreign key relationships to return something which has something else. For instance, Student::has('classes')->get(); would return all students who have classes.
The method whereHas() is like a regular has(), but it lets you put constraints on the search. Unlike where(), this is done on the child table rather than the parent one. Here's an example:
$students = Student::where('name', 'Pingu') // constrains the students table
->whereHas('classes', function($query) {
$query->where('name', 'like', '%physics%'); // constrains the classes table
})->get();
In this highly realistic example, you'd want all students with a name of Pingu, who are taking some class in physics.
I'm working in Laravel 4, and I have a Child model with multiple EducationProfiles:
class Child extends EloquentVersioned
{
public function educationProfiles()
{
return $this->hasMany('EducationProfile');
}
}
If I wanted to get all the EducationProfiles for each kid under age 10 it would be easy:
Child::where('date_of_birth','>','2004-03-27')->with('educationProfiles')->all();
But say (as I do) that I would like to use with() to grab a calculated value for the Education Profiles of each of those kids, something like:
SELECT `education_profiles`.`child_id`, GROUP_CONCAT(`education_profiles`.`district`) as `district_list`
In theory with() only works with relationships, so do I have any options for associating the district_list fields to my Child models?
EDIT: Actually, I was wondering whether with('educationProfiles') generates SQL equivalent to:
EducationProfile::whereIn('id',array(1,2,3,4))
or whether it's actually equivalent to
DB::table('education_profiles')->whereIn('id',array(1,2,3,4))
The reason I ask is that in the former I'm getting models, if it's the latter I'm getting unmodeled data, and thus I can probably mess it up as much as I want. I assume with() generates an additional set models, though. Anybody care to correct or confirm?
Ok, I think I've cracked this nut. No, it is NOT possible to eager load arbitrary queries. However, the tools have been provided by the Fluent query builder to make it relatively easy to replicate eager loading manually.
First, we leverage the original query:
$query = Child::where('date_of_birth','>','2004-03-27')->with('educationProfiles');
$children = $query->get();
$eagerIds = $query->lists('id');
Next, use the $eagerIds to filterDB::table('education_profile') in the same way that with('educationProfiles') would filter EducationProfile::...
$query2 = DB::table('education_profile')->whereIn('child_id',$eagerIds)->select('child_id', 'GROUP_CONCAT(`education_profiles`.`district`) as `district_list`')->groupBy('child_id');
$educationProfiles = $query2->lists('district_list','child_id');
Now we can iterate through $children and just look up the $educationProfiles[$children->id] values for each entry.
Ok, yes, it's an obvious construction, but I haven't seen it laid out explicitly anywhere before as a means of eager loading arbitrary calculations.
You can add a where clause to your hasMany() call like this:
public function educationProfilesUnderTen() {
$ten_years_ago = (new DateTime('10 years ago'))->format('Y-m-d');
return $this->hasMany('EducationProfile')->where('date_of_birth', '>', $ten_years_ago)
}