I have a Laravel model called "Area" which contains "Elements".
Elements can be different Models (in this case a FreetextElement and a CheckboxElement). The whole thing is hooked up with a polymorphic pivot table,
which contains the area_id, the element_id and the element_type.
The basic relationship works fine.
If I for example say:
$area->freetextElements
Then I get all the freetextElements that are attached to that particular area.
My issue is that I'd like a relationship function, which gets all the elements that are attached to the area, regardless of their model.
Here are the areas relations:
public function freetextElements()
{
return $this->morphedByMany(ElementFreetext::class, 'element', 'coaching_element_area_element');
}
public function checkboxElements()
{
return $this->morphedByMany(ElementCheckbox::class, 'element', 'coaching_element_area_element');
}
//find a better solution for this
public function elements()
{
return array_merge( $this->freetextElements->all(), $this->checkboxElements->all());
}
The last function "elements" is just to illustrate what I'm trying to achieve.
Any suggestions? Thanks in advance.
Best Regards
So I have found a solution to this issue. It's not the cleanest solution.
So I'm still open to any additional feedback, but I thought I leave this here for other people.
I simply created a model for the pivot table entries. Area->Elements is the relationship to the pivot table entries and That pivot table model is related to the individual elements via it's own relation. Now I can chain the relation by saying: Area->Elements->Element. It's not optimal, but it gets the job done.
Related
In my app, you can create lists of roles that are attached to contacts. So you can assign the contact "Bob" the roles of "Gardener" and "Pet Sitter". Then you can create the list "People" and add "Gardener (Bob)" and "Pet Sitter (Bob)" to it.
I have the following tables:
contacts
id
name
roles
id
name
contact_role (pivot)
id
contact_id
role_id
lists
id
name
contact_role_list (pivot)
id
contact_role_id
list_id
Everything was working smoothly until the second pivot table linked to the first pivot table. My pivot tables are (currently) not having any models so I'm not sure if there is a built-in feature to tackle this in Laravel or if I need to think differently.
I currently have this in my List model:
public function list_roles(): BelongsToMany
{
return $this->belongsToMany(XYZ::class, 'contact_role_list', 'list_id', 'contact_role_id');
}
Is this even close? What do I put where it says XYZ::class?
Ok, so the below is doing what I want, but is there an even better way to do it? The key to solving my problem was to create a Model for ContactRole and changing extends Model to extends Pivot.
I placed this in my List Model:
public function list_roles(): BelongsToMany
{
return $this->belongsToMany(ContactRole::class, 'contact_role_list', 'list_id', 'contact_role_id');
}
And this in my ContactRole Model:
public function contact(): BelongsTo
{
return $this->belongsTo(Contact::class);
}
Now I could reach the contact data by using something like this: List::first()->contact_roles->first()->contact
Any way to use with, pivot or similar to tidy this up even more? Thanks!
I like to approach these issues in terms of Models rather than pivots. I think many new Developers in Laravel get over obsessed with what's going on in the Database which is fine, but theres a lot of Magic going on so you can write very simple code that does a lot of Heavy lifting, so that being said if I fully understand your problem
You have a Contacts Model
This model can have many roles
so in your contacts Model you need a role relationship
public function roles()
{
return $this->belongsToMany(Roles::class);
}
next of course you have a role Model (pun intended)
your each role can have many list
public function lists()
{
return $this->hasMany(List::class)
}
then the idea is now that you have roles on contacts and lists on roles you should be able to have many lists through contact
public function lists()
{
return $this->hasManyThrough(List::class, Role::class);
}
I've done similar things before and for your description it seems like that's the approach you might need to take.
I have a problem with Laravel relationships.
I need to make relationship based on this table:
issuer and friend need to be united. Relationship will return all rows where user id in issuer or in friend. At the moment code looks like this:
return DB::table('contacts')->select()->where('friend', $this->id)->orWhere('issuer', $this->id)->where('status', 'approved');
Previously I used that method, but there are no relationship, 'cause attach() is undefined.
private function contactsIssued() {
return $this->belongsToMany(User::class, 'contacts','issuer', 'friend');
}
private function contactsFriended() {
return $this->belongsToMany(User::class, 'contacts','friend', 'issuer');
}
public function contacts() {
return $this->contactsIssued()->union($this->contactsFriended()->toBase());
}
So, I need to make one relationship that has two foreign columns.
Sorry, my English can be broken, 'cause it's not my native language.
That's look like a one to many relationship but you are using belongsToMany which is many to many relationship and required a pivot table.
if you have user model that has many contact model then in your contact model you should use the one to many relationship by using belongsTo.
but if you have 3 table you didn't say that in you question then please edit you question and provide your models and the relations between them.
I want to define a relationship between tables, and I don't know where I'm going wrong.
These are my tables:
users
-id
-email
-level
restaurants
-id
-name
-user_id
menus
-id
-name
restaurant_menu
-restaurant_id
-menu_id
-price
In the users table, the field level will set by me with two words: [user] or [restaurant].
User Model
public function restaurant(){
return $this->hasOne(Restaurant::class);
}
Restaurant Model
public function menus(){
return $this->hasMany(Menu::class);
}
Menu Model
public function restaurants(){
return $this->belongsTo(Restaurant::class);
}
I expect the output of this code:
$result = $restaurant->where('id',2)->menus()->get();
To be records and relations, but i get the following error.
BadMethodCallException
Call to undefined method Illuminate\Database\Eloquent\Builder::menus()
What should I do?
IN user model
public function restaurant(){
return $this->hasMany(Restaurant::class,'user_id','id');
}
Restaurant model
public function menus(){
return $this->hasMany(Menu::class,'id','menu_id');
}
Menu model
public function restaurants(){
return $this->belongsTo(Restaurant::class);
}
As you aspect your output you need to write
$result = Restaurant::with('menus')->where('id',2)->get();
you will get relational data. Like which restaurants has which menus.
You also can use this for your scenario. Use this in your Restaurant model
public function menues(){
return $this>hasManyThrough(Menu::class,restaurant_menu::class,'menu_id','id','id','restaurant_id');
}
Relations you define are not available for you in the query scope of your builder instance the way you tried to call them. They are available in the context of your models. Including your relationships in the queries is done differently - you should check official documentation on the matter first.
In your case, if you want to select all menus that belong to specific restaurant you have to ways:
You can first fetch specific restaurant and then get it's menus via a relationship:
$restaurant = Restaurant::find(2);
$menus = $restaurant->menus;
You can query for menus via Menu model:
$menus = Menu::whereHas('restaurants', function ($query) {
$query->where('id', 2);
})-get();
Also your relations are set up wrong. Based on table structure you've provided your menus and restaurants are in many-to-many relationship. Therefore restaurants() relation method in Menu class needs to return BelongsToMany instance. So while you're at it I would strongly suggest for you to go over relationships documentation and watch examples until you get the concepts of how different relationships work in Laravel.
Actually,
you defined relations in a correct way. I think that, you have an issue about to get those relations on the eloquent queries. If you want to get menu relation of a specific restaurant; you have to implement something like that.
$restaurant = Restaurants::find(2);
$restaurant->menus(); // this will return an array of related menus.
You should read Laravel Offical documentation. There are Retrieving The Relationship headlines for each relationship definition.
There is a problem with your relationship. You have a one to many relationship between restaurant model and menu model. However, your table structure suggests that, they have a many to many model.
If you think your model is right then change the menus table in following way,
menus
-id
-name
-restaurant_id //new field
Also, delete the "restaurant_menu" table.
If you think your database is correct then try changing the model accordingly.
I am designing shop solution in Laravel 5.2.
Now, I am stuck with a problem. I am creating self relation (one product can have many related products), like this
public function related()
{
return $this->belongsToMany(self::class, 'related', 'product_id', 'related_id');
}
Now, let's presume I got array of related products ids from form. How can I mass assign them? Seems I cannot do this without creating model for Related. Or can I?
The pivot table for many to many relation doesn't need model.
So you have to create pivot table "related" and make on it "product" function to set the relation.
and this link discuss that point: https://laravel.com/docs/5.2/eloquent-relationships#many-to-many.
You can use sync function like $product->related()->sync(/* product ids array */); to manage the relation.
I've been working with PHP for years but have never really ventured out of procedural programming except when working with things like IPB and Magento. I'm trying to advance to the next level and get a better understanding of application structures, OOP, and some common PHP frameworks. That being said, I apologize if my question sounds immature or technically incorrect, I'm new to all of this.
Anyway, I was thinking about the structure of a simple forum. Forgetting about categories, tags, users, roles, advanced editors/bbcode, etc for now and just focusing on the topics and posts...
Because a topic is essentially a series of linked posts ordered by their created_at column, is there a necessity for an actual topics table or could one not simply have a parent column in the posts table? Topics would be identified as posts with a parent equal to their own id, null or 0; something that would otherwise be unused.
If that were the db schema, how would it be laid out in the code, and if relevant, Laravel? Could you still create a Topic model? What would be the pros and cons to having two models working from a single table?
Lastly, how would you approach it if you were creating it? Would you use two tables? A pivot table? Something else? Please explain why you would implement it that way.
For the database design, self referencing tables are a valid design pattern and useful in cases of nested hierarchies such as Categories that can contain sub-categories that can also contain sub-categories ect ect... In this case sub-categories are categories that have a parent but there is no other distinction between them.
It's up to you to decide if a Topic and Post is an identical entity with a parent-child relationship. Personally the way I define the objects I don't feel they are.
The topic-post relationship you're describing is probably more of a One to Many relationship with the topic being the owner or maybe even a Many to Many relationship. This depends on the answer to, "can your topic have many posts? Can your posts be part of many topics?"
If you answered yes and no, then it is a One to Many with topics being the parent aka owner in the relationship.
If you answered yes and yes, then you have a Many to Many relationship. In SQL these are represented by a table with two columns that reference id's from two tables.
If you answered no and yes, then you have a One to Many with posts being the parent aka owner in the relationship.
In laravel, depending on the relationship, your models would include a method that looks like this:
One to Many:
class Topic extends Eloquent
{
public function posts()
{
return $this->hasMany('Post');
}
}
Laravel One-to-Many Relationships
Many to Many:
In laravel the term "pivot table" refers to the table with references to the other objects.
class Post extends Eloquent
{
public function topics()
{
return $this->belongsToMany('Topic');
}
}
class Topic extends Eloquent
{
public function posts()
{
return $this->belongsToMany('Post');
}
}
Laravel Many-to-Many
Self referencing model:
For a self referencing parent child relationship like I explained before you could create something like this, as you can see it's just a one-to-many and the many-to-one in the same model.
class Category extends Eloquent
{
public function parent()
{
return $this->belongsTo('Category', 'parent_id');
}
public function children()
{
return $this->hasMany('Category', 'parent_id');
}
}
There is also the Polymorphic Relation.
This is useful when you have the same entity with just a different type. For example in this table you can have an insurance policy for an employee and a manager. The personType column in the insurancePolicies table defines who the insurance policy belongs to.
Image from codecommit.com
Our laravel models in this case would look like:
class InsurancePolicy extends Eloquent
{
public function insurable()
{
return $this->morphTo();
}
}
class Manager extends Eloquent
{
public function insurance()
{
return $this->morphMany('InsurancePolicy', 'person');
}
}
class Employee extends Eloquent
{
public function insurance()
{
return $this->morphMany('InsurancePolicy', 'person');
}
}
Most everything of what I've explained can also be found in the laravel docs