This question is best illustrated by an example:
users
id
name
roles
id
name
role_user
user_id
role_id
rank_id
group_id
...
ranks
id
name
groups
id
name
I can easily eager load a users table by specifying the following relationship in my User.php model:
public function roles() {
return $this->belongsToMany('Role');
}
Which will output the table below when calling User::with('roles'):
User | Role
-------------
Jon | Admin
Jan | Mod
However I have no idea how to extend this to include:
User | Role | Rank | Group
-----------------------------
Jon | Admin | Boss | Blue
Jan | Mod | Minion | Red
What I've tried doing User::with('roles', 'ranks', 'groups') but that is certainly wrong since I'm telling Laravel there are rank_user and group_user intermediate tables too but there aren't. What is the correct way?
PS: I know it's better to separate the ranks and groups into their own relationship/pivot tables, this is simply an example.
EDIT: Closest example I can find for this: https://github.com/laravel/framework/issues/2619#issuecomment-38015154
You can just treat your model's relations methods as ordinary queries and build upon them:
public function roles() {
return $this->belongsToMany('Role')
->join('role_user', 'role_user.role_id', '=', 'roles.id')
->join('ranks', 'ranks.id', '=', 'role_user.rank_id')
->join('groups', 'groups.id', '=', 'role_user.group_id');
}
Relations queries like the above are not so intuitive to understand when they get too complex, so it may be better to rethink database design, but in theory it's possible to manipulate them.
Related
I'm working on an older project that I've been tasked to speed up certain parts of while we work on a complete re-write since the code is just badly maintained, poorly written and outdated for what it's suppose to do.
I stumbled into an issue to the core of the project and because of this I can't change it without breaking almost everything else. So I need to load a "relation" the eloquent way (using Planning:with('availability') but there isn't a real foreign ID, it rather laps with multiple fields.
Would there be a way to load it all in one query with the overlapping fields rather than have it load separately creating an n+1 problem?
+--------------+-----------------+
| Planning | Availability |
+--------------+-----------------+
| planning_id | availability_id |
| date | date |
| startHour | startHour |
| stopHour | stopHour |
| candidate_id | candidate_id |
| section_id | section_id |
+--------------+-----------------+
From the above example you can see the overlapping fields are date, startHour, stopHour, candidate_id and section_id.
I tried get...attribute but that still loads with n+1, I tried including it with ->with(['availabilities']) but that doesn't work since I ask for the
model and not the relation:
Edit for more clarity:
Planning Model:
public function availabilities()
{
return Availability::where('section_id', $this->section_id)
->where('candidate_id', $this->candidate_id)
->where('planningDate', $this->planningDate)
->where('startHour', $this->startHour)
->where('stopHour', $this->stopHour)
->get();
}
public function availabilities2()
{
return $this->hasMany('App\Models\Availability', 'candidate_id', 'candidate_id')
}
Controller:
$plannings = Planning::with(['availabilities'])->get();
$plannings = Planning::with(['availabilities2' => function ($query) {
// $this is suppose to be Planning model but doesn't work
$query->where('section_id', $this->section_id)
->where('planningDate', $this->planningDate)
->where('startHour', $this->startHour)
->where('stopHour', $this->stopHour);
// ---- OR ---- //
// Don't have access to planning table here
$query->where('section_id', 'planning.section_id')
->where('planningDate', 'planning.planningDate')
->where('startHour', 'planning.startHour')
->where('stopHour', 'planning.stopHour');
}])->get();
First of all to be able to load my relation I took one of the keys that matched and took the one which had the least matches which in my case was section_id.
So on my Planning model I have a function:
public function availabilities()
{
return $this->hasMany('App\Models\Availability', 'section_id', 'section_id');
}
This way I can load the data when needed with: Planning:with('availability').
However since I had a few other keys that needed to match I found a way to limit this relation by adding a subquery to it:
$planning = Planning::with([
'availabilities' => function ($query) {
$query->where('candidate_id', $this->candidate_id)
->where('startHour', $this->startHour)
->where('stopHour', $this->stopHour);
},
// Any other relations could be added here
])
->get();
It's not the best way but it is the only way I found it not getting too much extra data, while also respecting my relationship
When you want to use multiple fields in where() method you most insert a array in the where() method:
This document can help you
change your code to this:
return Availability::where([
['section_id', $this->section_id],
['candidate_id', $this->candidate_id],
['planningDate', $this->planningDate],
['startHour', $this->startHour],
['stopHour', $this->stopHour]
])->firstOrFail();
I have a new Laravel 5.8 application. I started playing with the Eloquent ORM and its relationships.
There is a problem right away that I encountered.
I have the following tables. (this is just an example, for testing reasons, not going to be an actual application)
Login table:
--------------------------
| id | user | data_id |
--------------------------
| 1 | admin | 1 |
| 2 | admin | 2 |
| 3 | admin | 3 |
--------------------------
Data table:
--------------
| id | ip_id |
--------------
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
--------------
IP table:
----------------------
| id | ip |
----------------------
| 1 | 192.168.1.1 |
| 2 | 192.168.1.2 |
| 3 | 192.168.1.3 |
----------------------
What I wanted is to get the IP belonging to the actual login.
So I added a hasOne relationship to the Login table that has a foreign key for the Data table:
public function data()
{
return $this->hasOne('App\Models\Data');
}
Then I added a hasOne relationship to the Data table that has a foreign key for the IP table:
public function ip()
{
return $this->hasOne('App\Models\Ip');
}
Once I was done, I wanted to retrieve the IP address for the first record of the Login table:
Login::find(1)->data()->ip()->get();
But I get this error:
Call to undefined method Illuminate\Database\Eloquent\Relations\HasOne::ip()
What am I missing here and how can I get the IP of that login in the correct way? Do I need a belongsTo somewhere?
1st error: Wrong relationship definition
Laravel relationships are bi-directional. On one-to-one relationships, you can define the direct relationship (HasOne) and the inverse relationship (BelongsTo)
The direct relationship should be:
HasOne HasOne
[ Login ] <----------- [ Data ] <----------- [ IP ]
And the inverse relationship should be:
BelongsTo BelongsTo
[ Login ] -----------> [ Data ] -----------> [ IP ]
See Eloquent: Relationships - One-to-One docs for details on how defining it.
Note that you don't need to define both directions for a relationship unless you need it. In your case, I think you just need to define the belongsTo direction.
2nd error: You are calling the relationship method, not the relationship itself
When you do:
Login::find(1)->data()->ip()->get();
You are calling the method data that defines your relationship, not the related model. This is useful in some cases, but not on your case.
The correct is call the relationship magic property instead:
Login::find(1)->data->ip;
Note that we don't use the () and we do not need the get() here. Laravel takes care of loading it for us.
Use Eager Loading
Laravel Eloquent have a Eager Loading for relationships that's very useful in some cases because it pre-loads your relationships, and reduce the quantity of queries you do.
In the situation that you described (loading a single Login model) it doesn't make any performance improvement, but also it doesn't slow down.
It's useful when you load many models, so it reduces your database query count from N+1 to 2.
Imagine that you are loading 100 Login models, without eager loading, you will do 1 query to get your Login models, 100 queries to get your Data models, and more 100 queries to get your Ip models.
With eager loading, it will do only 3 queries, causing a big performance increase.
With your database structure:
Login belongsTo Data
Data hasOne Login
Data belongsTo IP
IP hasOne Data
After fixed your methods you can use of your relations like this
$login = Login::with(['data.ip'])->find(1);
You can try like this:
Login
public function data()
{
return $this->belongsTo('App\Models\Data', 'data_id');
}
Data
public function ip()
{
return $this->belongsTo('App\Models\Ip', 'ip_id');
}
$login = Login::with(['data.ip'])->find(1);
And inside data you will have ip like $login->data->ip.
I'm trying to achieve something that is similar to Laravel's hasManyThrough, but I'm not sure my DB is set up appropriately or I'm just missing something.
I am trying to display a page for admins to show all of the sites we support. I would like to have a simple column that shows a distinct count of how many customers are attached to each site. To do this, I was going to go through the orders table and retrieve a distinct list of users, then simply use the ->count() method inside my view.
Here is my DB setup (simplified):
sites table (primary key: 'id'):
id | ...
users table (primary key: 'id'):
id | first_name | last_name | ...
orders table (primary key: 'order'):
id | order | user_id | site_id | ....
Site model:
public function customers()
{
return $this->hasManyThrough('App\User', 'App\Order', 'site_id', ' id')->distinct();
}
I realize right away that the key difference between my DB setup and the documentation is I do not have an order_id in my users table, but it doesn't make sense that I do since a user can have many orders.
It is worth noting: I also have a table user_orders. I'm not sure if I should be using that instead. user_orders has the following set up:
id | user_id | order
You can see that it is simply an intermediate table to hold connections between users and orders (remember order is the PK in orders, not id).
So, can anyone help me understand what I am doing wrong?
You could get away with a Join. I give you this sample code to guide you
public function customers()
{
return $this->hasMany('App\Order')
->leftjoin('users', 'users.id', 'orders.user_id')
->groupBy('users.id'); //Is this needed?
//Above code will return you a collection of Order though, but with the user data.
//Let's try using the User model
return App\User::whereHas('orders', function($query) use ($this->id) {
$query->where('site_id', $this->id);
})->get();
}
I'm making a table that essentially maps rows in a table to rows in another table where the structures are as follows:
|--- Words --| |- Synonyms -|
|------------| |------------|
| id | | id |
| en | | word_id |
| ko | | synonym_id |
| created_at | | created_at |
| updated_at | | updated_at |
|------------| |------------|
Now then, I know I can essentially have the words model have many Synonyms through a function like:
public function synonyms()
{
return $this->hasMany('Synonym');
}
No problem, but this method always gets it by the the word_id, and I would like to get it from word_id OR synonym_id that way I don't have to make multiple entries in the DB.
Is there anyway I can do this?
Check laravel docs Eloquent relationships. It would only get word_id because that's the only foreign key I believe.
Also why do you have synonym_id in your Synonyms table?
I believe you are looking for polymorphic relationship.
http://laravel.com/docs/eloquent#polymorphic-relations
I think your best bet is to create a many-to-many relationship with words on itself using the synonyms table as your pivot table.
Add this to your Word model.
public function synonyms()
{
return $this->belongsToMany('Word', 'synonyms', 'user_id', 'synonym_id');
}
Using it:
$word = Word::where('en', '=', 'someword')->first();
foreach($word->synonyms as $synonym) {
// This method would probably return the same word as a synonym of itself so we can skip that iteration.
if($synonym->en == $word->en) {
continue;
}
// Echo the synonym.
echo $synonym->en;
}
I'm a bit confused on you wanting to be able to find synonyms by the word_id or synonym_id but I think if you are using the many-to-many, it won't matter because if you know the synonym, it's still technically just a word, and you'd do the exact same thing.
I have the following db table set up
+--------------+ +--------------+ +-----------------------+
| users | | clients | | user_clients |
+--------------+ +--------------+ +----------------------+
| id | | id | | usersid |
| name | | name | | clientid |
| authid | | email | +----------------------+
| (plus) | | (plus) |
+-------------+ +-------------+
I have set up the a relationship table [b]user_clients[/b] with foreign keys to the relevant db, so userid is link to users->id and clientid is linked to clients->id.
Dependant on the Users Authid is how many clients are linked:
Authid 1: User can only have one client associated to them.
Authid 2: User can only have one to many clients associated to them
Authid 3: User has access to ALL clients.
So as i am new to this relationship side of laravel currently i would do a lot of querying to get some details eg:
I would done something like:
$userClient =UsersClients::select('clientid')->where('userid','=',$userid)->get();
Then I would probably loop through the result to then get each client details and output to the page.
foreach($userClient as $i ->$cleint){
echo '<div>' .$cleint->name . '</div>';
........
}
Would this be an old way and could it be handled better??
----------------EDIT---------------
i have managed to sort it as the following:
User Model:
public function clients() {
return $this->hasMany('UsersClients','userid');
}
User Controller
$selectedUserClients = User::find(24)->clients;
I get the same out come as my previous result as in client id's 1 & 2, but now how to get the client details from the actual client db basically is there an easier way that the following:
foreach ($selectedUserClients as $key => $client) {
$clientInfo = Client::select('id','clientname')->where('id','=',$client->clientid)->get();
echo $clientInfo[0]->clientname;
}
The users_clients table needs it's own ID column in order for many-to-many relationships to work.
On your User Model, try
public function clients()
{
return $this->belongsToMany('Client','user_clients','userid','clientid');
}
Now you can find the clients assigned to each individual user with
User::find(24)->clients.
You could also do the inverse on your Client model...
public function users()
{
return $this->belongsToMany('User','user_clients','clientid','userid');
}
This would allow you to find all the users belonging to each client
Client::find(42)->users;
I would also like to mention that it's best practice to use snake case for your id's such as user_id or client_id.
Your table names should be plural. users and clients.
Your pivot table should be snake_case, in alphabetical order, and singular. client_user.
This would make working with Eloquent much easier because it's less you have to worry about when setting up the relationships and it might be easier for someone else to help you work on your project.
Instead of return $this->belongsToMany('Client','user_clients','userid','clientid'); all you'd have to do is return $this->belongsToMany('Client'); which should keep your app much cleaner and easier to read.