Call to a member function getQuery() on null Laravel Eloquent - php

Question

I have worked a lot with Laravel and never got the following error:
Call to a member function getQuery() on null at /vendor/laravel/framework/src/Illuminate/Database/Eloquent/Builder.php line 558.
I'm trying to get a record with all the relationships specified. The code that is causing that error is the following:
$id = 7;
$compra = Compra::where('id', $id)
->with(['certificado',
'certificado.duracionServicios',
'certificado.duracionServicios.servicio',
'certificado.duracionServicios.servicio.traducciones' => function($query){
$query->whereHas('idiomas', function($q){
$q->where('codigo_region', 'es_MX');
});
},
'user'])
->first();
If I take out the first() method, I can print the object instance of Builder, but when I try to use it or even use get(), that exception is thrown. Laravel version I'm using is 5.5.
Model Compra
namespace App\Models\Sitio;
use Illuminate\Database\Eloquent\Model;
class Compra extends Model
{
protected $table = 'compras';
protected $fillable = ['folio',
'fecha_compra',
'subtotal',
'total',
'user_id',
'direccion_id',
];
protected $dates = ['created_at', 'updated_at'];
/**
* Get the value of the model's route key.
*
* #return mixed
*/
public function getRouteKey()
{
$hashids = new \Hashids\Hashids(config('app.name'), 5);
return $hashids->encode($this->getKey());
}
public function certificado(){
$this->hasOne('App\Models\Sitio\Certificado', 'compra_id');
}
public function user(){
return $this->belongsTo('App\User', 'user_id');
}
}
Model Certificado
namespace App\Models\Sitio;
use Illuminate\Database\Eloquent\Model;
class Certificado extends Model
{
protected $table = 'certificados';
protected $fillable = ['fecha_servicio',
'hora_servicio',
'compra_id',
];
protected $dates = ['created_at', 'updated_at'];
public function compra(){
return $this->belongsTo('App\Models\Sitio\Compra', 'compra_id');
}
public function duracionServicios(){
return $this->belongsToMany('App\Models\Sitio\DuracionServicio', 'certificados_duracion_servicios', 'certificado_id', 'duracion_id');
}
}
Model DuracionServicio
namespace App\Models\Sitio;
use Illuminate\Database\Eloquent\Model;
class DuracionServicio extends Model
{
protected $table = 'duracion_servicios';
protected $fillable = ['costo',
'servicio_id',
];
protected $dates = ['created_at', 'updated_at'];
public function certificados(){
return $this->belongsToMany('App\Http\Models\Sitio\Certificado', 'certificados_duracion_servicios', 'duracion_id', 'certificado_id');
}
public function servicio(){
return $this->belongsTo('App\Models\Sitio\Servicio', 'servicio_id');
}
public function traducciones(){
return $this->hasMany('App\Models\Sitio\DuracionServicioTraduccion', 'duracion_id');
}
}
Model Servicio
namespace App\Models\Sitio;
use Illuminate\Database\Eloquent\Model;
class Servicio extends Model
{
protected $table = 'servicios';
protected $fillable = ['seccion_id'];
protected $dates = ['created_at', 'updated_at'];
public function traducciones(){
return $this->hasMany('App\Models\Sitio\ServicioTraduccion', 'servicio_id');
}
public function duraciones(){
return $this->hasMany('App\Models\Sitio\DuracionServicio', 'servicio_id');
}
}
Model ServicioTraduccion
namespace App\Models\Sitio;
use Illuminate\Database\Eloquent\Model;
class ServicioTraduccion extends Model
{
protected $table = 'servicios_traducciones';
protected $fillable = ['nombre',
'descripcion',
'contenido',
'idioma_id',
'servicio_id',
];
protected $dates = ['created_at', 'updated_at'];
public function servicio(){
return $this->belongsTo('App\Models\Sitio\Servicio', 'servicio_id');
}
public function idioma(){
return $this->belongsTo('App\Models\Sitio\Idioma', 'idioma_id');
}
}
Model Idioma
namespace App\Models\Sitio;
use Illuminate\Database\Eloquent\Model;
class Idioma extends Model
{
protected $table = 'servicios_traducciones';
protected $fillable = ['nombre',
'codigo_region',
];
protected $dates = ['created_at', 'updated_at', 'deleted_at'];
public function servicios(){
return $this->hasMany('App\Models\Sitio\ServicioTraduccion', 'idioma_id');
}
public function duraciones(){
return $this->hasMany('App\Models\Sitio\DuracionServicioTraduccion', 'idioma_id');
}
}

Answer 1

Ok, so the problem is in your Compra model.
You defined relationship like this:
public function certificado()
{
$this->hasOne('App\Models\Sitio\Certificado', 'compra_id');
}
You forgot to add return. It should be:
public function certificado()
{
return $this->hasOne('App\Models\Sitio\Certificado', 'compra_id');
}

Answer 2

You can't call get_query() on a ->first().
->first() will return the first result of your query, and so execute the SQL query (after the first() you get a null result if no result, or your query result object). You should be able to use get_query() or get() if you remove the first() as you'll have an eloquent query instance, not a result object or collection.

Answer 3

You need to build up a query here by calling the query() method first.
$id = 7;
$compra = Compra::query()->where('id', $id)
->with(['certificado',
'certificado.duracionServicios',
'certificado.duracionServicios.servicio',
'certificado.duracionServicios.servicio.traducciones' => function($query){
$query->whereHas('idiomas', function($q){
$q->where('codigo_region', 'es_MX');
});
},
'user'])
->get();
or you can use ->first();