I have a quick question on how to define the below relationship
I have a USER that can belong to Many Councils, Many Schools and Many Businesses.
Now I know I can have a pivot table for all the above something like
council_user
school_user
business_user
This means I can pull out of the DB all councils a user belongs to, all businesses etc
To save me doing this is there a better approach that having 3 pivot tables, could I use Many To Many Polymorphic Relations and do it that way, if so does any one know how that would look as a table structure?
I feel it would be something like...
business
id - integer
name - string
council
id - integer
name - string
school
id - integer
name - string
userables
user_id - integer
userable_id - integer
userable_type - string
If so do I remove the userable_is and userable_type from my USER table and have this extra userables table?
Does any one know how this works, have I totally misunderstood what Polymorphic Relations does?
In Many to Many polymorphic relationship, you should have userables table along with users table. and userable_id and userable_type should be in userables table not in users table.
userables table:
user_id userable_id userable_type
1 1 App\Business
1 2 App\School
...
Business, School and Council Model:
public function users()
{
return $this->morphToMany('App\User', 'userable');
}
User Model:
public function businesses()
{
return $this->morphedByMany('App\User', 'userable');
}
public function schools()
{
return $this->morphedByMany('App\User', 'userable');
}
public function councils()
{
return $this->morphedByMany('App\User', 'userable');
}
then, this gives all the businesses of user with user_id 1.
$users=User::find(1);
foreach($user->businesses as $business)
{
print_r($business->name);
}
See Many to many polymorphic relation in doc.
Related
I have 3 tables:
structurals
id
name
indicators
id
name
groupings
id
structural_id
indicator_id
And Result:
#structural name
indicator name
indicator name
#structuralname
indicator name
I've used method hasMany & hasManyThrough but errors.
In this case, an indicator may belong to one or more structural. And a structural can have one or more indicators.
What this describes is a many-to-many relationship where groupings is only a pivot table. So you should be using the belongsToMany instead:
class Indicator extends Model
{
public function structurals()
{
return $this->belongsToMany(Structural::class, 'groupings');
}
}
class Structural extends Model
{
public function indicators()
{
return $this->belongsToMany(Indicator::class, 'groupings');
}
}
Docs: https://laravel.com/docs/eloquent-relationships#many-to-many
You can also remove the id column from the groupings table, as it is unnecessary.
I don't understand how to connect three tables in Laravel.
users> id, ...
groups> id, ...
group_user> id_group, id_user
I want to return all groups to me auth()->user()->groups.
Thanks in advance.
According to your explanation, group_user table holds many-to-many relationship between Group and User model. In case of a many-to-many relationship, you actually don't need a GroupMember model. This kind of table which holds many-to-many relationship is called pivot table. Read more from the Official Documentation
The first argument is the Model you are relating to, the second one is the name of the pivot table, and third argument is the foreign key name of the model on which you are defining the relationship, while the fourth argument is the foreign key name of the model that you are joining to
User.php
class User
{
public function groups()
{
return $this->belongsToMany(Group::class,'group_user','id_user','id_group');
}
}
Here's what I want to achieve, we have Staff and every staff can have one Position for a department, as well as one Designation for a department and multiple Additional Charges for multiple departments, one department per Additional Charge. And I want to store all the responsibilities in the staff_responsibilities table
I have a staff table with the following columns
id
name
email
Then I have staff_responsibilities table with the following columns:
staff_id
designation_id
department_id
responsibility_type_id
Responsibility types can be Position and Additional Charge and one staff can have multiple designations with Additional Charge responsibility.
Then I have a responsibility_types table with the following columns:
id
name
// I have no way to tell this relationship to look for a responsibility type 2 (2 is the id of the responsibility called `Designation`)
public function designation()
{
return $this->hasOne(StaffResponsibility::class);
}
// I have no way to tell this relationship to look for a responsibility type 2
public function position()
{
return $this->hasOne(StaffResponsibility::class);
}
// Gives error: Syntax error or access violation: 1066 Not unique table/alias: 'staff_responsibilities'
public function additionalCharges()
{
return $this->belongsToMany(StaffResponsibility::class, 'staff_responsibilities','designation_id');
}
Any help would really be appreciated.
staff_responsibilities table
responsibility_types table
designations table
Here's what I want to achieve, we have Staff and every staff can have one Position for a department, as well as one Designation for a department and multiple Additional Charges for multiple departments, one department per Additional Charge.
It sounds to me like it would be beneficial to create a model for Position, Designation and Additional Charges. It feels like you may need to normalize your database or to change staff_responsibilities as a pivot table.
But hard to say without knowing your application.
To answer your question, you could add some scopes in StaffResponsibility
class StaffResponsibility extends Model{
public function scopeDesignation($query)
{
return $query->where('responsibility_type_id','=',2);
}
}
and use it
public function designation()
{
return $this->hasOne(StaffResponsibility::class)->designation();
}
And the last one is a hasMany relation and not a manyToMany according to what you wrote:
public function additionalCharges()
{
return $this->belongsTo(StaffResponsibility::class, 'staff_responsibilities','designation_id')->additionalCharges();
}
I'm learning Laravel and Laravel eloquent at the moment and now I try to solve a problem using relations in Laravel.
This is what I want to archive:
The database holds many sport clubs. A sport club has a lot of teams. Each team has games. The teams table has a column named club_id. Now I want to create Eloquent relations to get all games of a club.
Here is what I got so far:
Club model
id => PRIMARY
public function games()
{
return $this->hasMany('App\Models\Games')->whereHas('homeTeam')->orWhereHas('guestTeam');
}
Game model
home_id => FOREIGN KEY of team ; guest_id => FOREIGN KEY of team
public function homeTeam()
{
return $this->belongsTo('App\Models\Team','home_id')->where('club_id','=', $club_id);
}
public function guestTeam()
{
return $this->belongsTo('App\Models\Team','guest_id')->where('club_id','=', $club_id);
}
Team model
id => PRIMARY ; club_id => FOREIGN
In my controller all I want to do is Club::findOrFail($id)->games()
Executing the code above returns a SQL error that the games table does not have a column named club_id.
What is the correct way to create this kind of relation?
Thanks!
EDIT
Thanks to Nikola Gavric I've found a way to get all Games - but only where club teams are the home or away team.
Here is the relation:
public function games()
{
return $this->hasManyThrough('App\Models\Game','App\Models\Team','club_id','home_id');
}
How is it possible to get the games where the home_id OR the guest_id matches a team of the club? The last parameter in this function does not allow an array.
There is method to retrieve a "distant relationship with an intermediary" and it is called Has Many Through.
There is also a concrete example on how to use it which includes Post, Country and User, but I think it will be sufficient to give you a hint on how to create games relationship inside of a Club model. Here is a link, but when you open it, search for hasManyThrough keyword and you will see an example.
P.S: With right keys naming you could achieve it with:
public function games()
{
return $this->hasManyThrough('App\Models\Games', 'App\Models\Teams');
}
EDIT #01
Since you have 2 types of teams, you can create 2 different relationships where each relationship will get you one of the type you need. Like this:
public function gamesAsHome()
{
return $this
->hasManyThrough('App\Models\Games', 'App\Models\Teams', 'club_id', 'home_id');
}
public function gamesAsGuests()
{
return $this
->hasManyThrough('App\Models\Games', 'App\Models\Teams', 'club_id', 'guest_id');
}
EDIT #02
Merging Relationships: To merge these 2 relationships, you can use merge() method on the Collection instance, what it will do is, it will append all the records from second collection into the first one.
$gamesHome = $model->gamesAsHome;
$gamesGuests = $model->gamesAsGuests;
$games = $gamesHome->merge($gamesGuests);
return $games->unique()->all();
Thanks to #HCK for pointing out that you might have duplicates after the merge and that unique() is required to get the unique games after the merge.
EDIT #03
sortBy also offers a callable instead of a attribute name in cases where Collection contains numerical indexing. You can sort your Collection like this:
$merged->sortBy(function($game, $key) {
return $game->created_at;
});
When you define that Club hasMany games you are indicating that game has a foreign key called club_id pointing to Club. belongsTo is the same but in the other way. These need to be coherent with what you have on your database, that means that you need to have defined those keys as foreign keys on your tables.
Try this...
Club model
public function games()
{
return $this->hasMany('App\Models\Games');
}
Game model
public function homeTeam()
{
return $this->belongsTo('App\Models\Team','home_id');
}
public function guestTeam()
{
return $this->belongsTo('App\Models\Team','guest_id');
}
Your Query like
Club::where('id',$id)->has('games.guestTeam')->get();
I have four tables in database: groups, specialties, lessons, group_lesson. It's structures:
groups
id
specialty_id
name
specialties
id
name
lessons
id
specialty_id
group_lesson (UNIQUE INDEX lesson_id, group_id)
lesson_id
group_id
date
My models look like that for now:
class Group extends Eloquent {
public function specialty() {
return $this->belongsTo('Specialty');
}
}
class Lesson extends Eloquent {
public function specialty() {
return $this->belongsTo('Specialty');
}
}
class Specialty extends Eloquent {
public function lessons() {
return $this->hasMany('Lesson');
}
public function groups() {
return $this->hasMany('Group');
}
}
I need get additional fields in Group model look like that
Group - Eloquent model
name - string
lessons - collection of Lesson models of Group Specialty
date - date from group_lesson table
I've tried different relationships and combinations, but it's doesn't work. Please help me to write correct relationships.
You can use eager-loading to access relational data through relationships, and can even chain relationships further. As a rule of thumb, if you can draw a path to from 1 model to another through a relationship, you can eagerload all the relevant and relational data for that with chained eager-loads.
Laravel Eager Loading
As an example
$speciality_group = Speciality::with('group','lessons')->find($id);
Even though you are only getting a single instance of the speciality model, the related data is hasMany, meaning multiple records. You need to loop through these records using a foreach loop to access the relevant data for them, or alternitavely add additional closures in your initial query to load only a single related model.
foreach($speciality_group->group as $group)
{
echo $group->name;
}
You will need to do this for both instances where you want to display related information.