Laravel hasMany relationship not resturning values without parentheses - php

Question

So I have this model, say City. And it has a OneToMany relationship with another model, say, Citizen.
On the city model, I have defined a relationship helper function
public function citizens()
{
return $this->hasMany(Citizen::class, 'city_id', 'id');
}
Now my problem is that, in a command, I have :
$cities = City::with('citizens')->get();
foreach ($cities as $city) {
$citizens = $city->citizens->pluck('user');
}
Yet it doesn't return anything. To get values I must turn this line to
$cities = City::all();
foreach ($cities as $city) {
$citizens = $city->citizens()->get()->pluck('user');
}
Does anyone have a clue how this might happen ? This started happening today with no apparent reason.
EDIT
To further illustrate the situation,
$cities = City::with('citizens')->get();
foreach ($cities as $city) {
dd($city->citizens()->count()); // => 5
dd($city->citizens->count()); // => 0
}
Here are the models definitions
// City.php
class City extends Model
{
use Searchable;
protected $table = 'cities';
public $incrementing = false;
protected $perPage = 20;
protected $fillable = [
'name',
'unique_code',
'extra_attributes'
];
protected $casts = [
'id' => 'string',
'codes' => 'array',
'extra_attributes' => SchemalessAttributes::class,
];
public static function boot()
{
parent::boot();
self::creating(function ($model) {
$model->id = $model->id ?: Str::orderedUuid();
});
}
public function toSearchableArray(): array
{
return [
'name' => $this->name,
];
}
public function citizens()
{
return $this->hasMany(Citizen::class, 'city_id', 'id');
}
}
// Citizen.php
class Citizen extends Model
{
public $incrementing = false;
protected $perPage = 20;
protected $table = "citizens";
protected $fillable = [
'user_id',
'level_id',
'city_id',
];
public static function boot()
{
parent::boot();
self::creating(function ($model) {
$model->id = $model->id ?: Str::orderedUuid();
});
}
public function user() {
return $this->hasOne(User::class, 'id', 'user_id')->withTrashed();
}
public function city() {
return $this->hasOne(City::class, 'id', 'city_id');
}
}

Answer 1

the relation between City and Citizen is City hasMany Citizens...
In Laravel, hasMany relation reverse is belongsTo Not hasOne, see Laravel doc
so you should correct the relation In Citizen Model like this:
public function city() {
return $this->belongsTo(City::class, 'city_id');
}

Answer 2

There are two issues, one of which OMR has highlighted (you've used an incorrect relationship in your Citizen class), but that isn't the main issue. You're trying to pluck another relationship but unless you explicitly tell it to, Laravel won't eager load that relationship. You've only told it to eager load the Citizen relationship, not the User relationship. Thankfully, Laravel does support nested relationships. You need to update your query thusly:
$cities = City::with('citizens.user')->get();

Answer 3

The best way to solve this issue is by eager loading the citizens when you're getting your cities, that way you wont be executing too many queries (as you will have to get citizens for each city individually), it will save you a lot of execution time in the future when the database gets bigger if you do this :
$cities = City::with('citizens')->get();
foreach($cities as $city) {
$items = $city->citizens->pluck('...');
}