I have users and user_roles tables, and id of user_roles is used as foreign key in users. I fetched data from users using User::with('userRole')->find($user). In returned result userRole is present, however it is empty, instead it was supposed to have data from user_roles for the particular foreign key.
Please, share what can be the possible issues with the functionality or if anyone can explain working of laravel associations in brief.
/* User Model */
public function userRole()
{
return $this->belongsTo('App\UserRole');
}
/* UserRole Model */
public function user()
{
return $this->hasMany('App\User');
}
Thank You,
Many to many relationships in Laravel often require you to have 2 models and 3 tables. One to many relationships require you to have 2 models and 2 tables. One to one relationship also requires you to have 2 models and 2 tables.
Many to many relationship
Let's take User and Role models, since each User can have multiple roles and one Role can be assigned to different users, you will naturally want a Many to many relationship. Now, you will need to create an intermediate table in which you will store the results, why? Because you already defined both User and Role and since it is Many to many none of those objects will have any identifier of the other one inside of them, but rather will have their own identifier in the intermediate table, and this is how Laravel fetches the relationship, it connects Models primary key with foreign key inside of the intermediate table.
One to many relationships
Let's take User and Role models again and let's say that this time, one Role can be assigned to multiple users, but one User can ONLY have 1 Role. Naturally you will have a field role_id inside of your User model and you will connect role_id from users with id from roles.
One to one relationships
Lets take User and Role models again :D Let's say you want to create a separate Role for every user, then you will have 2 models and 2 tables where your users table will have all the users and your roles table will contain id, name, user_id and now when you try to retrieve the relationship, if you define one to one laravel will return only 1 result, no matter if you have multiple same user_id on the roles table, Laravel will return only 1 role because you told him explicitly it's 1-to-1 relationship.
EDIT:
Here is an example of one to one relationship:
/* User Model */
public function userRole()
{
return $this->belongsTo('App\UserRole', 'user_role_id', 'id');
}
#Tim and #Nikola
Thank you, for your efforts mates.
However, I found the reason behind the problem. It was because the wrong naming of userRole function in User model.
I was using foreign key of user_roles as user_roles_id in users table and defined function with name of userRole in User model. This leads to ORM not found the relevant column for attaching user_roles data.
The solution is either I have to change the name of user_roles_id to user_role_id or userRole function name to userRoles. And I choose the first one and it worked fine. :)
For reference on the naming conventions of laravel please refer to Laravel - Database, Table and Column Naming Conventions?.
Related
I have a table where I need to save the ids in array, you can see the items in
events_who is a foreign keys. Any solution where I can create a Relationship in my Model to get the data from the foreign keys? I tried belongsToMany and it doesn't work. :(
Any suggestions?
Let's assume we are having 2 models: Event and Person
And a Person can participate to multiple Event
Based on the mentioned relationships, you need to create a pivot table called event_person and define two belongsToMany() relationships in both models:
In the Person model, the relationship will look like:
public function events()
{
return $this->belongsToMany(Event::class, 'event_person');
}
Laravel / MySQL (Relational Database) don't really work this way. You should check out Many to Many Relationships in this case.
Example table schema/layout:
users
|id|name|password|
events
|id|title|body|
event_user (pivot table)
|event_id|user_id|
Usually there won't be an array in a column, you should use tables instead. Besides, normally a foreign key would be a table name(singular) following by _id.
User
uid
Provider
pid
Resolution
rid
ProviderResolution
prid
pid
rid
active
ProviderResolutionUser
prid
uid
class Provider extends Model {
public function resolutions()
{
return $this->belongsToMany('App\Models\Resolution')->withPivot('active')->withTimestamps();
}
}
class Resolution extends Model {
public function providers()
{
return $this->belongsToMany('App\Models\Provider')->withPivot('active')->withTimestamps();
}
}
class User extends Model
{
}
Trying to create a Eloquent relationship with this.
I'm trying to figure out how to fit user into this model. It seems like it's suppose to belongsToMany. Do I need to create a class that represents the pivot?
Then from the case of the User how would I query a list resolutions?
You didn't ask but I personally think it's a lot easier to let the primary key of each table be 'id.' Also, in the case of ProviderResolution, unless you have a specific case for it, you don't need (and shouldn't use) 'prid' at all. Just 'pid', 'rid' and 'active' should be sufficient. The 'pid' and 'rid' make the composite primary key on their own. If you add yet another key ('prid'), then there will be a three-key composite which will technically enable you to have duplicates with your other two primary keys. Yuck. Example: PRID:1, PID:1, RID:1, then PRID:2, PID:1, RID:1. Now you have duplicates but your record is technically still unique because of the PRID key. But, maybe you want it this way for some reason?
For the answer I'm going to assume you are using Laravel 5.4+.
So first off, you don't need a class for the pivot. And secondly, you are currently trying to create a relationship between the user and the existing pivot table between Provider and Resolution by creating a table called 'provider_resolution_user'. If you want to query resolutions for a user, just use the relationship methods which gives you access to the attributes on the pivot table and the related models/tables.
First, setup the 'hasMany' relationships in both classes: Users and Resolutions (Providers already has a relationship to Resolutions, so you can use that relationship if you want to see the related Provider.) Then you'll need a pivot table called 'resolution_user'. Put the 'uid' and the 'rid' in the table. Make the relationships to the corresponding foreign key fields to their parent tables.
Now you can access the relationship directly like:
$user->resolutions->rid (or whatever the attribute is you want)
The previous example assumes you have already created a way to insert records into the pivot table (resolution_user) that relate the user and the resolution together.
If you want to access one of the attributes on the pivot table, 'pivot' creates an object instance with it's own attributes (from the table). You can access it like this:
$user->resolutions->pivot->active;
Of course, these methods are chainable so if you just wanted to see the active resolutions, you could also add a ->where statement.
Hope that helps and wasn't too muddy. I'm happy to clarify any points if need be.
EDITED ANSWER:
Because what you want to do is to disable a row in the provider_resolution table and have that reflect on the correct user, then just create a relationship in both the User model and the Resolution model. So when you disable a row in provider_resolution (pid, rid, active), you can lookup the appropriate user to update by using the inverse relationship between resolution and user. This should give you the user that is assigned to that particular resolution/provider combination. If for some reason you do need to find the user based on a unique combination of the TWO: resolution AND provider, then we might need to talk about polymorphic relationships. Let me know.
In my Laravel5 app I have users, tasks, and user_tasks. A user can complete a task multiple times:
User:
id
name
...
Task:
id
name
value
...
UserTask:
id
user_id
task_id
completed_on
If this were a normal many-to-many relationship I would have this function in the user class:
class User extends Model {
// ...
public function tasks(){
return $this->belongsToMany(Task::class, 'user_tasks', 'user_id', 'task_id');
}
}
But I believe this means that user_id/task_id is a primary key on user_tasks. How do I change the relationships between Task and User if I want duplicate user_id/task_id entries in the join table?
Second question, what if I want a list of all unique tasks a user has completed, regardless of how many time a user has completed them?
EDIT: Sorry, I wasn't trying to mean it would place a unique key on those columns. I meant that it seems like belongsToMany should be used in a situation where there is only one join between any pair of User and Task objects, so situations where user_id/task_id could be a unique key.
I was working on making a group functionality for my website which uses a many to many relationship between groups and users.
My User model looks like this:
public function groups(){
return $this->belongsToMany('App\Group')->withPivot('role')->withTimestamps();
}
My Groups model looks like this:
public function users(){
return $this->belongsToMany('App\User')->withPivot('role')->withTimestamps();
}
So my third column has the name of role which is a string variable and is set to a default of "member" for members of my group and I set it to "admin" for the actual user who creates a new group. But I want the admin to have the option of making multiple members admins as well which would require me to check weather the current current user who sent the request is an admin or not. If he is, then I wanna be able to take his request of making a member an admin which would require me to update the role for that particular "member" to an "admin".
In the laravel documentation it only shows you how to attach and detach data in a pivot table and else where I have only seen methods of retrieving data from the first two columns but how can I do the same for additional columns and also be able to update it using the updateExistingPivot method?
You could access the column simply using pivot e.g :
$user->pivot->role
Take a look at Retrieving Intermediate Table Columns in documentation Eloquent Relationships.
Hope this helps.
I would like to use Laravel 5 Models to retrieve a relationship, but i dont know which relation type i should use and how to implement it.
i have 4 database tables:
Users
Roles
Permissions
role_permission
i need to retrieve all the permissions for a "User" based on its "role_id" column.
I've created 3 models:
User
Role
Permission
The database table "users" holds 2 columns:
id
role_id
The database table "roles" holds 2 columns
id
name
The database table "permissions" holds 2 columns
id
name
The database table "role_permission" holds 3 columns that defines which Role is associated to which Permission.
role_id
permission_id
flag
What i want to achieve is the following syntax:
$user->role // Get the associated "Role"
$user->role->permissions // Get the associated permissions for a "Role"
App\Role::find(1)->permissions // Get the associated permissions for a "Role"
i did read the Laravel documentation about model relations but i really dont get it. Does someone understand what i'm trying to achieve and how to implement it in the Models? maybe with some simpel code examples so i can understand the relations and how they work?
Thanks in advance.
The way that you have your database defined, you have defined the following relationships: a one-to-many between role and users, and a many-to-many between roles and permissions. It can also be stated that a role has many users, a user belongs to a role, a role has many permissions, and a permission has many roles.
In Laravel, one-to-one relationships are modeled using a hasOne/belongsTo set, one-to-many relationships are modeled using a hasMany/belongsTo set, and many-to-many relationships are modeled using a belongsToMany/belongsToMany set.
The relationships are defined in the models below:
User:
Since the users table contains the foreign key to the roles table (role_id), the User model is on the belongsTo side of the one-to-one/one-to-many relationship.
class User extends Model {
public function role() {
return $this->belongsTo('\App\Role');
}
}
Role/Permission:
The many-to-many with permissions is done by both models having a belongsToMany relationship. The Laravel convention for the pivot table name is the combination of the singular table names, in alphabetical order, with an underscore separator, so it should be 'permission_role'. Since the pivot table name doesn't follow convention, it must be specified in the relationship definition. Also, since you have an extra field on the pivot table, you need to specify access to that field with the withPivot() method on the relationship.
class Role extends Model {
public function users() {
return $this->hasMany('\App\User');
}
public function permissions() {
return $this->belongsToMany('\App\Permission', 'role_permission')->withPivot('flag');
}
}
class Permission extends Model {
public function roles() {
return $this->belongsToMany('\App\Role', 'role_permission')->withPivot('flag');
}
}