Laravel One-to-One关系无效

Question

I have 2 database tables => mobile_phones , mobile_users

Schema for mobile_phones

• phone_id (primary key , auto_increment)

• phone_name (varchar(150))

• phone_model (int (11))

Schema for mobile_users

• user_id (primary key , auto_increment)

• username (varchar(150))

• mobile_phone_id (foreign key referencing mobile_phones(phone_id))

Model class for mobile_phones

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class MobilePhone extends Model
{
    protected $primaryKey = "phone_id";
    public $timestamps = false;
    protected $table = "mobile_phones";
    protected $fillable = array("phone_name","phone_model");

    public function mobileUser()
    {
        return $this->hasOne("MobileUser","mobile_phone_id");
    }

}

Model class for mobile_users

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class MobileUser extends Model
{
    protected $primaryKey = "user_id";
    public $timestamps = false;
    protected $table = "mobile_users";
    protected $fillable = array("username","mobile_phone_id");

    public function mobilePhone()
    {
        return $this->belongsTo("MobilePhone","phone_id");
    }


}

I am trying to establish One-to-One relationship between MobileUser and MobilePhone models but it isn't happening. Below is my code in Controller's action -

public function query()
    {
       $getUsername = MobilePhone::find(1)->username;        
       echo $getUsername;
    }

The above code gives me NULL when I do a var_dump() I did check similar questions on SO and they used with() (but this isn't necessary). I am referring Laravel 5.2 docs and they state that we can access relate record in another relation using Eloquent's dynamic properties. Link to that docs is here

Please Help !!

Answer 1

Something like this :

public function query()
    {
       $getUsername = MobilePhone::find(1)->mobileUser;        
       echo $getUsername->username;
    }

Answer 2

When doing this:

public function query()
    {
       $getUsername = MobilePhone::find(1)->username;        
       echo $getUsername;
    }

You try to access a username property out of a MobilePhone number, which is incorrect.

Try this:

public function query()
    {
       $getUsername = MobilePhone::find(1)->mobileUser->username;        
       echo $getUsername;
    }

Also I encourage you to use the with statement as it will preload all dependencies needed (means 1 single query) instead of eager loading it (many queries)

Answer 3

You need to call the function of your model so do the following

public function query()
{
       $getUsername = MobilePhone::find(1)->mobileusers;        
       echo $getUsername->username;
}