I have many to many related two tables, "roles" and "users" with pivot table as "user_roles".
In Role model
$this->belongsToMany('users', 'user_roles');
In User model
$this->belongsToMany('roles', 'user_roles');
Is this a valid relation?
You want a pivot table and a many to many relationship using a pivot table like you said.
What you are trying to do is explained in Laravel documentation - Eloquent
No. The first parameter should be the class name of the related model:
$this->belongsToMany('User', 'user_roles');
$this->belongsToMany('Role', 'user_roles');
Otherwise you should be fine if you foreign keys follow the convention...
See the documentation for more info
Related
I have a Users table that can store 8 different types of users. Depending on the user type, I have some other tables with the specific data set for it. So, I would like to use the ID from the Users table as a foreign key and primary key at the same time for those tables. But I am new at Laravel and I don't know how to do that to fit the conventions or, if it is not possible, how to do that when defining my models and one to one relations. Can someone help me? Thanks!
EDIT: Sorry, I think my explanation is not clear enough. Let's say I have 4 tables: users, user_types, customer_organzations, partners, and customers. I would like to use ID, that is PK of users, as a foreign key and primary key for tables customer_organizations, partners and customers, that have different information since they are different type of users in my application but all them login against users table. I don't care user_types table. I think I know how to deal with it.
You haven't given us much in terms of your table structure, so assuming you have a simple one-to-one relationship between a users table and a user_types table, the following would create the required relationship.
In your user_types table migration
$table->foreignId('user_id')->constrained();
The above will add your foreign key to the table and create the relationship back to the users table (this is done 'magically' using conventions so naming is important).
Then in your eloquent models, add the relationships between the models:
User.php
public function type()
{
return $this->hasOne(UserType::class);
}
UserType.php
public function user()
{
return $this->belongsTo(User::class);
}
I cannot find a solution, likely to how I am phrasing the question. I have a model called Invoice and it has the following relationship:
public function manifests(){
return $this->morphedByMany(carrier_manifest::class, 'invoiceable')->withPivot(['amount','rate_id','notes']);
}
As you can see, in the pivot, I have a table called rate_id. I would like to be able to add a relationship to another model based on the value of the rate_id (the model just being called ChargeRates). Is there a way I can do this in order to access a field in the ChargeRates model called label?
You'd want to actually implement the pivot table as a model if it has relationships and functionality on its own.
From a database concern, a many to many relationship between Table A and Table B is really just a one-to-many relationship between Table A and the pivot table and a one-to-many relationship between Table B and the pivot table.
Therefore, implementing your relationships with a pivot model using hasMany or morphMany is a way for you to accomplish what you're after.
Let's say I have two tables:
Users: id, name, country_id
Countries: id, name
Of course each user can only have one country, but each country is assigned to multiple users.
So would it be safe to have a User model that utilizes hasOne and a Country model that uses belongsToMany method?
Documentation makes it seem like you can't mix and match different types of relationships.
What you are describing is actually a One To Many relationship, where one country has many users. Your Country model should utilize a hasMany relationship, while your user would have a belongsTo relationship.
#Andy has already answered well.
Anyway, my advice is to always think in the following way to create a One-To-One, One-To-Many, or a Many-To-Many relationship:
In the table with the foreign key (if any) use belongsTo
In the other table without the foreign key use hasOne or hasMany
In any of them have a foreign key, you have a Many To Many relationship and you must use belongsToMany in both of them (you need the pivot table, of course).
There's a missing link I fail to understand.
I use migrations to create database tables and I define the relationships there. meaning.. if I have a person table and a job table and I need a one to many relationship between the person and jobs, I'd have the job table contain a "person_id".
When I seed data or add it in my app, I do all the work of adding the records setting the *_id = values etc.
but somehow I feel Laravel has a better way of doing this.
if I define that one to many relationship with the oneToMany Laravel Eloquent suports:
in my Person model.....
public function jobs()
{
return $this->hasMany('Jobs);
}
what's done on the database level? how do I create the migration for such table? Is Laravel automagically doing the "expected" thing here? like looking for a Jobs table, and having a "person_id" there?
Yep, Laravel is doing what you guess in your last paragraph.
From the Laravel documentation for Eloquent Relationships (with the relevant paragraph in bold):
For example, a User model might have one Phone. We can define this
relation in Eloquent:
class User extends Model {
public function phone()
{
return $this->hasOne('App\Phone');
}
}
The first argument passed to the hasOne method is the name of the
related model. Once the relationship is defined, we may retrieve it
using Eloquent's dynamic properties:
$phone = User::find(1)->phone;
The SQL performed by this statement
will be as follows:
select * from users where id = 1
select * from phones where user_id = 1
Take note that Eloquent assumes the foreign key of the relationship based on the model name. In this case, Phone model is assumed to use a user_id foreign key.
Also note that you don't actually have to explicitly set the foreign key indexes in your database (just having those "foreign key" columns with the same data type as the parent key columns is enough for Laravel to accept the relationship), although you should probably have those indexes for the sake of database integrity.
There is indeed support to create foreign key relationships inside migration blueprints and it's very simple too.
Here is a simple example migration where we define a jobs table that has a user_id column that references the id column on users table.
Schema::create('jobs', function($table)
{
$table->increments('id');
$table->integer('user_id')->unsigned();
$table->foreign('user_id')->references('id')->on('users');
});
You can also use some other methods that laravel provides such as onDelete() or onUpdate
Of course to understand better the options that are available to you please read the documentation here.
Edit:
Keep in mind that Eloquent is just using fluent SQL wrapper and behind the scenes there are just raw sql queries, nothing magical is happening, fluent just makes your life a lot easier and helpers you write maintainable code.
Take a look here about the Query Builder and how it works and also, as #Martin Charchar stated , here about Eloquent and relationships.
Laravel 4.1 introduced the hasManyThrough relationship. This assumes 2 relating hasMany relationships. I however would like to retrieve the hasMany relationships of a belongsTo relationship instead.
Project (id, contact_id, ...)
Contact (id, ...)
Address (id, contact_id, ...)
For each project, I would like to get all addresses.
I managed to do this using a belongsTo() relationship and some additional table joining. However, a belongsTo relationship binds a single object, instead of an array.
So my thoughts are I either need to:
... be able to override the LIMIT 1 behavior on belongsTo relationships
... or be able to override the hasManyThrough to work with a belongsTo as intermediate relationship.
It sounds like you are trying to set up a many-to-many relationship between Projects and Contacts, with a one-to-one relationship between Address and Contact. If that is the case you will need to create a pivot table "project_contact" with columns "project_id" and "contact_id" as well as any other columns (timestamps(), etc). Then you can set a "belongsToMany('Project')" relationship on the Contacts.
I'm not sure if that is what you're after, but it solves the problem as I understand it.