laravel 4 hasOne / hasMany / belongsTo不起作用

Question

I have some models belong to Activity Model.

in my Activity.php I had

<?php

class Activity extends \Eloquent {
     protected $fillable = [];

     public function activity_car_nums()
     {
         return $this->hasMany('ActivityCarNum');
     }

     public function newables()
     {
         return $this->hasMany('Newable');
     }

     public function serial_codes() 
     {
         return $this->hasMany('SerialCode');
     }

     public function applys()
     {
         return $this->hasMany('Apply');
     }

}

and in SerialCode.php, I had

<?php

class SerialCode extends \Eloquent {
     protected $fillable = ['code'];

     public function activity()
     {
         return $this->belongsTo('Activity');
     }
}

and in my controller, when I wrote

$serial_codes = [];
while(count($serial_codes) < $serial_code_total)
{
    $code = substr(md5(uniqid(rand(), true)),0,5);
    $serial_code = new SerialCode(['code' => $code]);

    if(!in_array($serial_code, $serial_codes))
    {
        $serial_codes[] = $serial_code;
    }
}

$activity->serial_codes()->saveMany($serial_codes);

it works.

But when it turns to

//this can get activity object
$activity = Activity::find($id);

//this can get the serial codes of the object above.
$serial_codes = SerialCode::whereActivityId($id)->get();

//this don't work, it returns null
$serial_codes = $activity->serial_codes;

for I really don't know why...

Can anybody help me please, and sorry for my poor English. Thank You. (If you need any code else please tell me.)

Answer 1

my model code:

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
use DB;
class Product extends Model
{
    public $table="s_products";
    protected $primaryKey = 'product_id';
    public function reviews()
        {
            return $this->hasMany('App\ProductReview');
        }
    public function attributes()
    {
        return $this->hasMany('App\AttributeMapping');
    }        
    public function images()
       {
           return $this->hasMany('App\Image');
       }  
}

Answer 2

I found the reason that why my model query cannot work, because the "_" in function name.

just change

public function serial_codes()

to

public function serialcodes()

then everything will go fine.

Thank to everybody.