Laravel返回模型created_at

I have:

Model

public function getUrlAttribute() {
    dd($this->created_at);
}

View

@foreach($item as $item)
    {{$item->url}}
    ...
@endforeach

But it returns null, when in fact every row in my table has a created_at datetime. What is going wrong here?

You have to return the value.

public function getUrlAttribute() {
    return $this->created_at;
}

I suspect that for whatever reason the created_at column was not selected when creating the model. What do you get if you do the following?

dd($item->toArray()); 

You can also access it more directly skipping

$this->getCreatedAtAttribute()

by doing:

public function getUrlAttribute() {
    dd($this->attributes['created_at']);
}