laravel Eloquent all() method queries the mysql date field and only returns the year

Mysql date_key field attribute is date,
After creating the model with laravel eloquent and using the all() method, the date_key field only returns the year.
I don’t know if it’s the model time format setting or something else, please give me some advice. The code is as follows:
Model:
class Rpt_ep_read extends Model
{

<code>//
protected $table = 'rpt_ep_read';
protected $primaryKey = 'date_key';</code>

}
Controller
use AppModelsRptdataWebRpt_ep_read;
class TestController extends Controller {
public function test(){

<code> $data = Rpt_ep_read::all(); 
 return $data;</code>

}
}
Return value:

mysql
CREATE TABLE rpt_ep_read (
date_key date NOT NULL COMMENT 'time',
cust_num int(11) NOT NULL COMMENT 'number of users',
PRIMARY KEY (date_key )
) ENGINE =InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Using DB::table()->get() can return normally

Reply content:

Mysql date_key field attribute is date,
After creating the model with laravel eloquent and using the all() method, the date_key field only returns the year.
I don’t know if it’s the model time format setting or something else, please give me some advice. The code is as follows:
Model:
class Rpt_ep_read extends Model
{

<code>//
protected $table = 'rpt_ep_read';
protected $primaryKey = 'date_key';</code>

}
Controller
use AppModelsRptdataWebRpt_ep_read;
class TestController extends Controller {
public function test(){

<code> $data = Rpt_ep_read::all(); 
 return $data;</code>

}
}
Return value:

mysql
CREATE TABLE rpt_ep_read (
date_key date NOT NULL COMMENT 'time',
cust_num int(11) NOT NULL COMMENT 'number of users',
PRIMARY KEY (date_key )
) ENGINE =InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Using DB::table()->get() can return normally

Add public $incrementing = false; below your Model, otherwise Laravel’s default primary key is auto-incremented and will be converted to int and returned