select column from relationship besides main table [duplicate] - php

Question

I have two tables, User and Post. One User can have many posts and one post belongs to only one user.
In my User model I have a hasMany relation...
public function post(){
return $this->hasmany('post');
}
And in my post model I have a belongsTo relation...
public function user(){
return $this->belongsTo('user');
}
Now I want to join these two tables using Eloquent with() but want specific columns from the second table. I know I can use the Query Builder but I don't want to.
When in the Post model I write...
public function getAllPosts() {
return Post::with('user')->get();
}
It runs the following queries...
select * from `posts`
select * from `users` where `users`.`id` in (<1>, <2>)
But what I want is...
select * from `posts`
select id,username from `users` where `users`.`id` in (<1>, <2>)
When I use...
Post::with('user')->get(array('columns'....));
It only returns the column from the first table. I want specific columns using with() from the second table. How can I do that?

Answer 1

Well I found the solution. It can be done one by passing a closure function in with() as second index of array like
Post::query()
->with(['user' => function ($query) {
$query->select('id', 'username');
}])
->get()
It will only select id and username from other table. I hope this will help others.
Remember that the primary key (id in this case) needs to be the first param in the
$query->select() to actually retrieve the necessary results.*

Answer 2

You can do it like this since Laravel 5.5:
Post::with('user:id,username')->get();
Care for the id field and foreign keys as stated in the docs:
When using this feature, you should always include the id column and
any relevant foreign key columns in the list of columns you wish to
retrieve.
For example, if the user belongs to a team and has a team_id as a foreign key column, then $post->user->team is empty if you don't specifiy team_id
Post::with('user:id,username,team_id')->get();
Also, if the user belongs to the post (i.e. there is a column post_id in the users table), then you need to specify it like this:
Post::with('user:id,username,post_id')->get();
Otherwise $post->user will be empty.

Answer 3

For loading models with specific column, though not eager loading, you could:
In your Post model
public function user()
{
return $this->belongsTo('User')->select(['id', 'username']);
}
Original credit goes to Laravel Eager Loading - Load only specific columns

Answer 4

When going the other way (hasMany):
User::with(['post'=>function($query){
$query->select('id','user_id');
}])->get();
Don't forget to include the foreign key (assuming it is user_id in this example) to resolve the relationship, otherwise you'll get zero results for your relation.

Answer 5

In Laravel 5.7 you can call specific field like this
$users = App\Book::with('author:id,name')->get();
It is important to add foreign_key field in the selection.

Answer 6

If you want to get specific columns using with() in laravel eloquent then you can use code as below which is originally answered by #Adam in his answer here in response of this same question, the answer's main code is as below :
Post::with('user:id,username')->get();
So i have used it in my code but it was giving me error of 1052: Column 'id' in field list is ambiguous, so if you guys are also facing same problem
Then for solving it you have to specify table name before the id column in with() method as below code:
Post::with('user:user.id,username')->get();

Answer 7

I came across this issue but with a second layer of related objects. #Awais Qarni's answer holds up with the inclusion of the appropriate foreign key in the nested select statement. Just as an id is required in the first nested select statement to reference the related model, the foreign key is required to reference the second degree of related models; in this example the Company model.
Post::with(['user' => function ($query) {
$query->select('id','company_id', 'username');
}, 'user.company' => function ($query) {
$query->select('id', 'name');
}])->get();
Additionally, if you want to select specific columns from the Post model you would need to include the user_id column in the select statement in order to reference it.
Post::with(['user' => function ($query) {
$query->select('id', 'username');
}])
->select('title', 'content', 'user_id')
->get();

Answer 8

In your Post model:
public function userWithName()
{
return $this->belongsTo('User')->select(array('id', 'first_name', 'last_name'));
}
Now you can use $post->userWithName

Answer 9

There is another alternative you can eager load specific columns
public function show(Post $post)
{
$posts = $post->has('user')->with('user:id,name,email,picture')->findOrFail($post->id);
return view('your_blade_file_path',compact('posts);
}
In your Post model you should have user relationship also
public function user()
{
return $this->belongsTo( User::class, 'user_id')->withDefault();
}
Note: It is mentioned in Laravel docs.
https://laravel.com/docs/8.x/eloquent-relationships#eager-loading-specific-columns

Answer 10

Note that if you only need one column from the table then using 'lists' is quite nice. In my case i am retrieving a user's favourite articles but i only want the article id's:
$favourites = $user->favourites->lists('id');
Returns an array of ids, eg:
Array
(
[0] => 3
[1] => 7
[2] => 8
)

Answer 11

If you use PHP 7.4 or later you can also do it using arrow function so it looks cleaner:
Post::with(['user' => fn ($query) => $query->select('id','username')])->get();

Answer 12

I faced the same issue while using belongsToMany relationship with my user model (Laravel 8.x.x).
After a long search and trial and test method. I found out this answer
You have to make sure you are selecting the id's and any foreign keys that would be needed for the relationship from either side of that relationship. This allows Eloquent to match up parents to their children.
Original credit goes to https://stackoverflow.com/a/64233242/1551102
So I included
Groups::select('groupid')
...
And it worked like a charm. Although now I want to know how to hide the groupid field after fetching.
I know I can simply loop through the array and remove it. But is there any other method? potentially a simpler and better one.

Answer 13

You can also specify columns on related model at the time of accessing it.
Post::first()->user()->get(['columns....']);

Answer 14

You can try this code . It is tested in laravel 6 version.
Controller code
public function getSection(Request $request)
{
Section::with(['sectionType' => function($q) {
$q->select('id', 'name');
}])->where('position',1)->orderBy('serial_no', 'asc')->get(['id','name','','description']);
return response()->json($getSection);
}
Model code
public function sectionType(){
return $this->belongsTo(Section_Type::class, 'type_id');
}

Answer 15

Be careful that if you don't add the key column(s) it won't return anything. If you want to show only the username without the id you could instead define the $visible/$hidden properties within the Model, like so:
app/Models/User.php
protected $visible = ['username'];
Then it will retrieve only username column with:
Post::with('user')->get();
Hiding the key columns:
Alternatively you could hide the key column(s) and then retrieve only the columns you wish.
app/Models/User.php
protected $hidden = ['id'];
Specify which columns you want including the key or else it won't return anything, but this will actually only return the username, because id is $hidden.
Post::with('user:id,username')->get();

Answer 16

Now you can use the pluckmethod on a Collection instance:
This will return only the uuid attribute of the Post model
App\Models\User::find(2)->posts->pluck('uuid')
=> Illuminate\Support\Collection {#983
all: [
"1",
"2",
"3",
],
}

Answer 17

Try with conditions.
$id = 1;
Post::with(array('user'=>function($query) use ($id){
$query->where('id','=',$id);
$query->select('id','username');
}))->get();

Answer 18

So, similar to other solutions here is mine:
// For example you have this relation defined with "user()" method
public function user()
{
return $this->belongsTo('User');
}
// Just make another one defined with "user_frontend()" method
public function user_frontend()
{
return $this->belongsTo('User')->select(array('id', 'username'));
}
// Then use it later like this
$thing = new Thing();
$thing->with('user_frontend');
// This way, you get only id and username,
// and if you want all fields you can do this
$thing = new Thing();
$thing->with('user');

Answer 19

EmployeeGatePassStatus::with('user:id,name')->get();