根据关系Laravel 5.8和Eloquent更新数据库表

Question

I have a problem with updating tables that belongTo another table. I have a users table and a recipes table. The Recipe model belongsTo the User model and the User model hasMany Recipe.

Each recipe is shown in my index view as a small card and on that card, as well as on each individual show page, I am printing recipe->author. When a recipe is created, it takes the username attribute from the users table and sets this as the author attribute on the recipes table. However, when I update the username of a user, the author attribute in the recipes table does not update accordingly.

User Model

 public function recipes(){
        return $this->hasMany('App\Recipe');
    }

Recipe Model

 public function user(){
        return $this->belongsTo('App\User');
    }

Can I possible add some logic in my UserController to account for this when I update a user?

UserController@update

$user = Auth::user();

        $this->validate(request(), [
            'name' => 'required',
            'username' => 'required',
        ]);

          // Handle File Upload 
          if(request()->hasfile('profile_pic')){
            // Get filename with extension
            $fileameWithExt = request()->file('profile_pic')->getClientOriginalName();
            // Get just filename
            $filename = pathinfo($fileameWithExt, PATHINFO_FILENAME);
            // Get just extension
            $extension = request()->file('profile_pic')->getClientOriginalExtension();
            // Filename to store
            $fileNameToStore = $filename . '_' . time() . '.' . $extension;
            // Upload Image
            $path = request()->file('profile_pic')->storeAs('public/profile_pictures', $fileNameToStore);
        } else {
            $fileNameToStore = 'noimage.jpg';
        }

        $user->name = request('name');
        $user->username = request('username');
        $user->description = request('description');
        $user->location = request('location');
        if(request()->hasFile('profile_pic')){
            $user->profile_pic = $fileNameToStore;
        }
        $user->push();

        $user_id = Auth::user()->id;
        return redirect()->route('user', ['id' => $user_id]);
    }

I have read the Laravel docs and can't find anything that will quite do what I am looking for. Would appreciate any guidance!

Answer 1

You mean you store username in users , and you want to store the exact username in the author of recipes ?

Why not you just reference the name using relationship $recipe->user->username . It would query your users table based on your user_id in your recipes and get that username for you.

So that you're not storing duplicating data in your database. There should be only one Single Source of Truth . You can get your user data based on your user_id , there's no point to store another set of data and keep updating it when the source is changed.

If you find querying whole User model a bit of heavy, then you can use Recipe::with('users:id,username')->get() to query only the username .

Or

If you want to maintain the current $recipe->author , you can:

// Recipe class
public function getAuthorAttribute() {
  return $this->user->username;
}

Answer 2

If you set up the foreign keys on your migration files, you may add the ->onUpdate('CASCADE') clause to the username foreign on the recipes table migration.

Note: the onCascade foreign constraint would work outside of Laravel too, as it relies only on the database engine's support for foreign keys.

Anyways, be careful with your validation as you have to be sure the new chosen username isn't already used by someone else.

Assuming your User model is connected to the users table and has an id primary key, make sure that you set the username column as unique in the database, and **validate* user input accordingly.

The former is done by editing once again your migration.

The latter is solved by modifying your rules like these ones:

// Do not forget the Rule import at the top of your controller
use Illuminate\Validation\Rule;

// Then in your method
$this->validate(request(), [
    'name' => 'required',
    'username' => [
        'required',
        Rule::unique('users', 'username')->ignore($user)
    ]
]);

Note: if you modify migrations you have to rerun them in order to apply the modification.