Laravelのリレーションがやっとわかったので備忘録(え、いまさら?)

今回作成するモデル

Modelの書き方

(親側)User.php

<?php

namespace App\Models;
use App\Models\Profile;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;


class User extends Model {
    use HasFactory;
    protected $fillable = [
        "id",
        "username",
        "email",
        "password"
    ];

    public function profile(){
        return $this->hasOne(Profile::class);
    }

}

(子側)Profile.php

<?php

namespace App\Models;
use App\Models\User;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Profile extends Model {
    use HasFactory;
    protected $fillable = [
        "user_id",
        "name",
        "description",
    ];

    public function user(){
        return $this->belongsTo(User::class);
    }
    
}

Migrationファイルの書き方

example.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;


return new class extends Migration
{
    /**
     * Run the migrations.
     */
    public function up(): void
    {
        Schema::create("users", function(Blueprint $table) {
            $table -> bigIncrements('id');
            $table -> string("username");
            $table -> string("email");
            $table -> string("password");//平文保存は危険なので絶対しない(これは例だから無視)
            $table -> timestamps();
        });

        Schema::create("profile", function(Blueprint $table){
            $table -> bigIncrements("id");
            $table -> string("name");
            $table -> string("description");
            $table -> foreignId("user_id")->constrained("users")
            $table -> timestamps();
        }
    }
}

追加

example.php

$user = User::create([
    "username" => $username,//固有のユーザーネーム
    "email" => $email,//メールアドレス
    "password" => bcrypt($password)//パスワードをbcrypt()を使ってハッシュ化
]);
$profile = Profile::create([
    "name" => $name,//文字列型の変数(名前が格納)
    "description" => $description, //文字列型の変数(自己紹介が格納)
    "user_id" => $user->id,
    "user" => $user
])

取得

(親から子)example.php

$user = User::find(1)->with("profile"//Modelで指定したメソッド名);
$profile = $user->profile;//Modelで指定したメソッド名

(子から親)example.php

$profile = Profile::where("name", $name)->find();
$user = $profile->user;

注意

• where/getを使うと戻り値はCollection型になるのでforearchで1個づつ取り出してリレーションを参照しなければならない。