I have a user model which stores basic user information such as username, password etc.
There are also 3 types of user, Student, Staff and Parent. Each type also has a seperate model. For example, there is a Student model which belongs to a User model.
I also have a relationships table, which stores relationships between students and parents. This relationship is stored in the User model.
If I do something like:
App\Student::first()->user->relations;
It happily returns a collection of related parents.
In my Students model, I have a method called hasParent() which accepts a given user ID, and checks to ensure the student has a parent with that id. In that method, I have the following:
public function hasParent($parent)
{
return $this->user->relations->where('id', $parent)->count() === 1;
}
However, this returns an error Cannot call 'where' on a non-object. If I debug further, $this->user->relations returns an empty array.
The problem is, like above, if I call the methods separately, I get the results I want.
So to clarify, if I run:
App\Student::first()->user->relations;
This returns a collection of users just fine.
In my Student model however, if I call:
$this->user
Then I get the correct student
If I call
$this->user->relations
I get an empty array. Which doesn't make sense! Can anyone shed any light on this, or what I might be doing wrong? If you need any further info, please let me know.
You need to call where on the relation like below.
public function hasParent($parent)
{
return $this->user->relations()->where('id', $parent)->count() === 1;
}
See the parenthesis after the relations. If you call the relation without the parenthesis Laravel returns you a collection. To get the builder you need to call the relation with the parenthesis.
I'd suggest - to avoid creating a huge query overhead (which you'll do by calling where and count on the Query builder, not the collection) - to do what you're doing already, except using Illuminate Collections filter-method:
public function hasParent($parent)
{
return $this->user->relations->filter(function($relation) use ($parent){return $entity->id === $parent;})->count() === 1;
}
Related
I'm currently struggling with retrieving data towards a parent model. I'll drop my database, classes, and things I've tried before.
I have 4 tables: sales_orders, products, work_orders, and product_sales_order (pivot table between sales_orders and products).
SalesOrder.php
class SalesOrder extends Model
{
public function products()
{
return $this->belongsToMany(Product::class)
->using(ProductSalesOrder::class)
->withPivot(['qty', 'price']);
}
}
ProductSalesOrder.php
class ProductSalesOrder extends Pivot
{
public function work_orders()
{
return $this->hasMany(WorkOrder::class);
}
public function getSubTotalAttribute()
{
return $this->qty* $this->price;
}
}
WorkOrder.php
class WorkOrder extends Model
{
public function product_sales_order()
{
return $this->belongsTo(ProductSalesOrder::class);
}
public function sales_order()
{
return $this->hasManyThrough(
ProductSalesOrder::class,
SalesOrder::class
);
}
}
So, what I want to retrieve sales order data from work order since both tables don't have direct relationship and have to go through pivot table and that is product sales order. I've tried hasOneThrough and hasManyThrough but it cast an error unknown column. I understand that error and not possible to use that eloquent function.
Is it possible to retrieve that sales order data using eloquent function from WorkOrder.php ?
You cannot achieve what you want using hasOneThrough as it goes from a table that has no ID related to the intermediate model.
In your example you are doing "the inverse" of hasOneThrough, as you are going from a model that has the ID of the intermediate model in itself, and the intermediate model has the ID of your final model. The documentation shows clearly that hasOneThrough is used exactly for the inverse.
So you still should be able to fix this, and use a normal relation as you have the sales_orders_id in your model SuratPerintahKerja, so you can use a normal relation like belongsTo to get just one SalesOrder and define it like this:
public function salesOrder()
{
return $this->belongsTo(SalesOrder::class, 'sale_orders_id');
}
If you want to get many SalesOrders (if that makes sense for your logic), then you should just run a simple query like:
public function salesOrders()
{
return $this->query()
->where('sale_orders_id', $this->sale_orders_id)
->get();
}
Have in mind that:
I have renamed your method from sales_order to salesOrder (follow camel case as that is the Laravel standard...).
I have renamed your method from sales_order to salesOrders for the second code as it will return more than 1, hence a collection, but the first one just works with one model at a time.
I see you use sale_orders_id, but it should be sales_order_id, have that in mind, because any relation will try to use sales_order_id instead of sale_orders_id, again, stick to the standards... (this is why the first code needs more parameters instead of just the model).
All pivot tables would still need to have id as primary and auto incremental, instead of having the id of each related model as primary... Because in SuratPerintahKerja you want to reference the pivot table ProdukSalesOrder but it has to use both produks_id (should have been produk_id singular) and sale_orders_id (should have been sales_order_id). So if you were able to use something like produk_sales_order_id, you could be able to have better references for relations.
You can see that I am using $this->query(), I am just doing this to only return a new query and not use anything it has as filters on itself. I you still want to use current filters (like where and stuff), remove ->query() and directly use the first where. If you also want to add ->where('produks_id', $this->produks_id) that is valid and doesn't matter the order. But if you do so, I am not sure if you would get just one result, so ->get() makes no sense, it should be ->first() and also the method's name should be salesOrder.
Sorry for this 6 tip/step, but super personal recommendation, always write code in English and do not write both languages at the same time like produks and sales orders, stick to one language, preferrably English as everyone will understand it out of the box. I had to translate some things so I can understand what is the purpose of each table.
If you have any questions or some of my code does not work, please tell me in the comments of this answer so I can help you work it out.
Edit:
After you have followed my steps and changed everything to English and modified the database, this is my new code:
First, edit ProductSalesOrder and add this method:
public function sales_order()
{
return $this->belongsTo(SalesOrder::class);
}
This will allow us to use relations of relations.
Then, have WorkOrder as my code:
public function sales_order()
{
return $this->query()->with('product_sales_order.sales_order')->first();
}
first should get you a ProductSalesOrder, but then you can access ->sales_order and that will be a model.
Remember that if any of this does not work, change all the names to camelCase instead of kebab_case.
i'm really new working with laravel 5.0, so I got this problem when I try to retrieve a result using a model. I have a users table, with a list of users who can be a manager or not, they can have assigned one or more companies, or none, a company table with companies which can have one or many managers, and a pivot table that I called companies_managers. I set up the relations in every model like this:
/***User model***/
public function companies()
{
return $this->belongsToMany('App\Company', 'companies_managers','id', 'manager_id');
}
and the same in Company model
public function managers()
{
return $this->belongsToMany('App\User', 'companies_managers', 'id', 'company_id');
}
I want to get the managers assigned to a company using a company id to get it, but it just gave me an huge object without the values I looking for (the names of the managers assigned to that company). This is the code that I tried:
$managers = Company::find($id)->managers();
I would appreciate any help you can give me
Using ->managers() (with the brackets) doesn't actually return the associated managers, but rather a Builder instance (the "huge object"), which you can then chain with additional parameters before finally retrieving them with ->get() (or another closure, like ->first(), ->paginate(), etc)
Using ->managers (without the brackets), will attempt to access the associated managers, and execute any additional logic to retrieve them.
So, you have 2 options:
$company = Company::with(["managers"])->findOrFail($id);
$managers = $company->managers;
Or
$company = Company::findOrFail($id);
$managers = $company->managers()->get();
Both of those will perform the necessary logic to pull the managers. ->with() and no brackets is slightly more efficient, doing it all in a single query, so bear that in mind.
You just need to split out your code;
// this will find the company based on the id, or if it cannot find
// it will fail so will abort the application
$company = Company::findOrFail($id);
// this uses the active company record and gets the managers based
// on the current company
$managers = $company->managers;
Thank you for your help guys, I solved the issue fixing the relations in the models to this:
return $this->belongsToMany('App\Company', 'companies_managers', 'manager_id', 'company_id');
and this
return $this->belongsToMany('App\User', 'companies_managers', 'company_id', 'manager_id');
The IDs that I had set were not the correct ones for belongsToMany function
And this
$managers = Company::find($id)->managers();
was a problem too, was a dumb mistake of my part. I solved the return of Builder instance using just return instead of dd(), in that way I got the values I looking for. Thanks everyone!
I've found some query result really unexpected.
It's Laravel 5.2
We have following entity:
User with method:
public function roles() : BelongsToMany
{
return $this->belongsToMany(Role::class)->withPivot('timestamp');
}
Each User can have many roles, so we have also Role entity (but it doesn't matter much in my question) and pivot table user_role with timestamp field (and ids of course), because we hold information about time, when User achieved specific role.
I want to get all Users with theirs last assigned Role
When I create query (in User context in some repository):
$this->with(['roles' => function($query) {
$query->orderBy('timestamp', 'desc');
}])->all();
the result will contain Users with Roles entities inside itself ordered by timestamp - it's ok. But I want to retrieve only one last role inside each User entity not all ordered.
So...
$this->with(['roles' => function($query) {
$query->orderBy('timestamp', 'desc')->limit(1);
}])->all();
And then I retrieve Users but only User which achieved some Role for the very last time contains it! All the other Users have their roles field containing empty array.
Why ordering was performed on each Users relation separately, but when I added limit it behaved like a global limit for all.
It drives me crazy...
Thanks for advices.
EDIT
I've created lastRoles() method to get all Roles ordered desc. But all, retrieving one is impossible.
public function lastRoles() : BelongsToMany
{
return $this->BelongsToMany(Roles::class)->withPivot('timestamp')->latest('timestamp');
}
And for testing:
$users = (new User())->with('lastRoles')->get();
But now I must iterate over Users and invoke lastRoles() on each one:
foreach ($users as $user) {
var_dump($user->lastRoles()->get()->first()->name);
}
Then I retrieve names of latest Roles assigned to each User.
So... There is no way to do it in one query? This is the only way?
For this to work, you would need a helper function:
public function latestRole()
{
return $this->hasOne(Role::class)->withPivot('timestamp')->orderBy('timestamp', 'DESC');
}
And then:
$this->with('latestRole')->get();
Credits to this awesome article.
When you eager load a relationship with query constraint(s), the query will be run once to load all relationships, not each one individually. This is the expected behavior. Think about it, eager loading exists to turn many queries into one query in order to optimize performance. There is only one query executed, so your limit constraint will limit the entire result set, rather than on a per model basis.
To circumvent this, you could try creating another belongsToMany method that adds the desired limit constraint. The following code is untested:
public function lastRole() : BelongstoMany
{
return $this->belongsToMany(Role::class)
->withPivot('timestamp')
->orderBy('timestamp', 'desc')
->limit(1);
}
Assuming this works, you can then simply change the relationship method from roles to lastRole and remove your query constraint:
$this->with('lastRole')->all();
So far I was extracting the relation objects as arrays and then doing something like:
App\Model::find($id)
But however is there a way to do something like:
Auth::user()->group()->members()
It works until Auth::user()->group but no further chaining. Please help if you've done something. Or I'm just newbie.
You could use eager loading to load the user's group and then load all of the members of that group.
$user = User::with(['group', 'group.members'])->find(1);
// OR if you already have a user object (Like when using the Auth facade)
$user = Auth::user()->load(['group', 'group.members']);
foreach ($user->group->members as $member) {
// Do something with a member
}
However, if you essentially want to jump down the structure a level, and get all the members related to a user, you could use the hasManyThrough relationship, in that a user has many members, through a group.
// In your User model
public function members()
{
return $this->hasManyThrough(Member::class, Group::class);
}
That way you can simply access the members directly through the user:
$members = Auth::user()->members;
Instead of doing a query to access the user's group and then doing another query to access that group's members, Laravel would use a single query with a join to get you the members.
Take a look at the hasManyThrough relationship here
Try this
Auth::user()->group->members
I am trying to figure out a relationship but I can't seem to solve the issue.
So what my script does first is checking if there is a valid session where status = 0.
Then I want to check if there is a valid trial where status = 0 ->first() associated with that session. And if so, I want to grab all the relevant data related by trial_id.
I understand what logic is required. However, I am wondering if there is a method to do this with as little commands as possible using Eloquent relationships.
Specifically, once i have the $session object. How can I filter the trials, in order to get the appropriate stimuli_tracker data?
The important components to the relationships for the table is as follows:
Sessions
id (has one to many relationship to trials(sessions_id)
user_id (foreign key)
status
Trials
id (one to many relationship with stimuli_tracker)
sessions_id (foreign key)
status
Stimuli_Tracker
trials_id (foreign key)
stimulus
stimulus_type
Sessions Model
class Sessions extends Model
{
protected $table = 'sessions';
public function stimuliTracker()
{
return $this->hasManyThrough('App\StimuliTracker', 'App\Trials', 'sessions_id','trials_id');
}
}
Trials Model:
class Trials extends Model
{
public function stimuli()
{
return $this->hasMany(App\StimuliTracker);
}
}
EDIT
I have tried in artisan tinker to
$object = \App\Session::where(arg);
then I tried to
$object->stimulus
but didn't work. I tried a few other fields but I only received null. Maybe I'm not getting how to grab the content properly
$object->stimulus is an undefined attribute based on what you've shown in your code.
To access the stimulus information for your session, you have to use the name of the relationship, which in this case is:
$object->stimuliTracker
The thing is that this will return an Eloquent Collection because it is a hasManyThrough relationship (which is a hasMany of a hasMany).
I'm assuming that the 'stimulus' attribute belongs to the StimuliTracker class. If this is the case, then you will need to loop through your StimuliTracker Collection to extract it:
foreach ( $object->stimuliTracker as $record )
{
$stimulus = $record->stimulus;
// do something with $stimulus
}
EDIT (Added):
If you are just looking for an array of the values in the 'stimulus' attribute, you can get that with the lists() method:
$stimulus_values = $object->stimuliTracker->lists('stimulus');