Level 104
get() will always return a Collection, use first() instead to return a single instance
return ClassDetailResource::collection(
ClassDetail::where('course_id',$request->id)->with('classes')->with('teach')->first()
);
10 likes
Mar 15, 2018
13
Level 4
Property [id] does not exist on this collection instance
Hello,I want to crate api with laravel,But my code show error like that.. Property [id] does not exist on this collection instance this is from my controller...
public function read(Request $request){
return ClassDetailResource::collection(ClassDetail::where('course_id',$request->id)->with('classes')->with('teach')->get());
}
this is ClassDetail model..
class ClassDetail extends Model
{
public function classes(){
return $this->hasMany('App\Class_');
}
public function teacher(){
return $this->belongsTo('App\Teacher');
}
public function teach(){
return $this->teacher()->select('id','name');
}
}
this is classdetail resource...
public function toArray($request)
{
return [
'id'=>$this->id,
'name'=>$this->name,
'count'=>count($this->classes),
'course_id'=>$this->course_id,
'classes'=>new ClassResource($this->whenLoaded('classes')->slice(0,3)),
];
}
this is Class Resource..
public function toArray($request)
{
return [
'id'=>$this->id,
'img_url'=>$this->img_url,
'status'=>$this->status,
'title'=>$this->title,
'description'=>$this->description,
'price'=>$this->price,
'teacher_id'=>new TeacherResource($this->whenLoaded('teach')),
'created_at'=>$this->created_at
];
}
it show error like that..
"message": "Property [id] does not exist on this collection instance.",
"exception": "Exception",
"file": "/home/aung/Desktop/conceptX/vendor/laravel/framework/src/Illuminate/Support/Collection.php",
"line": 1879,
Level 4
can't work sir @tykus .. show error like that
"message": "Method Illuminate\Database\Query\Builder::mapInto does not exist.",
"exception": "BadMethodCallException",
"file": "/home/aung/Desktop/conceptX/vendor/laravel/framework/src/Illuminate/Database/Query/Builder.php",
"line": 2575,
Level 8
Seems like you're trying to get the ID from collection instance instead of from an item IN that collection:
collect($classes)->id; // error
collect($classes)->first()->id; // no error
If you could provide the full error stacktrace, it would be easier to pinpoint the exact spot where this error occurs.
Level 8
Are you trying to take only one ClassDetail object or a collection of them?
1 like
Level 4
I want to take collection of them sir.... @maslauskast
Level 104
Your teach method is likely the issue here.; can you try the following instead:
return ClassDetailResource::collection(
ClassDetail::where('course_id',$request->id)->with('classes')->with('teacher:id,name')->first()
);
1 like
Level 24
in your read() method dd($request) and see if that has an id. If it does make sure that ClassDetail actually has a row with course_id equal to that
1 like
Level 4
now,I'm trying without teacher
return ClassDetailResource::collection(ClassDetail::where('course_id',$request->id)->with('classes')->first());
but still showing error like that.. @tykus
"message": "Method Illuminate\Database\Query\Builder::mapInto does not exist.",
"exception": "BadMethodCallException",
"file": "/home/aung/Desktop/conceptX/vendor/laravel/framework/src/Illuminate/Database/Query/Builder.php",
"line": 2575,
Level 4
Yes, it all correct @deansatch
Level 4
if I don't use new Class Resource in classdetail resource,it can work well. I change code from...
public function toArray($request)
{
return [
'id'=>$this->id,
'name'=>$this->name,
'count'=>count($this->classes),
'course_id'=>$this->course_id,
'classes'=>new ClassResource($this->whenLoaded('classes')->slice(0,3)),
];
}
To..
public function toArray($request)
{
return [
'id'=>$this->id,
'name'=>$this->name,
'count'=>count($this->classes),
'course_id'=>$this->course_id,
'classes'=>$this->classes->slice(0,3),
];
}
why can't use Class Resourece in ClassDetail Resource? but I need to use teacher.
Level 8
Because it's a one-to-many relationship.
Using this new ClassResource($this->whenLoaded('classes')->slice(0,3)) expects 'classes' relationship to be one-to-one or many-to-one, you should use this:
'classes' => ClassResource::collection($this->whenLoaded('classes')->slice(0,3)),
6 likes
Level 1
@maslauskast After 5 years still good answer and explanation) Thanks!
Level 1
In my case I was using a collection in my API when it expected a model instance. The collection does not have the id property, the model instance does.
Collection is a bag-o-stuff, not containing the properties and methods of a model class instance like id, name, email, etc., like a User model might have. Instead it has a lot of its own useful methods that work on collections of models (or other things).
So I had a query like Property::where('id', ... some way of selecting a random id which exists ->pluck('id')->toArray() )->get() which returned a collection instead of the $property instance I was expecting with the ->id field available.
I did $property = Property::inRandomOrder()->first() instead to get a collection of Property, and first() on that to get the actual model instance of a randomish Property, which then had the id property on it, so I could use $property->id.
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