LaravelEloquentORM怎么用_LaravelEloquentORM基础操作及高级查询技巧

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    // 可选：指定表名（如果不遵循复数规则）
    protected $table = 'users';

    // 可选：指定主键字段
    protected $primaryKey = 'id';

    // 可选：关闭自动维护 created_at 和 updated_at
    public $timestamps = false;

    // 允许批量赋值的字段
    protected $fillable = ['name', 'email', 'password'];
}

User::all();

User::where('name', 'John')->first();

User::where('active', 1)->get();

$user = new User;
$user->name = 'Alice';
$user->email = 'alice@example.com';
$user->save();

// 或使用 create 方法（需 fillable 配置）
User::create([
    'name' => 'Bob',
    'email' => 'bob@example.com'
]);

$user = User::find(1);
$user->name = 'New Name';
$user->save();

// 批量更新
User::where('active', 0)->update(['active' => 1]);

// 删除单个
$user = User::find(1);
$user->delete();

// 根据条件删除
User::where('created_at', '<', now()->subDays(30))->delete();

User::where('active', 1)->paginate(10);

User::orderBy('name', 'desc')->limit(5)->get();

class User extends Model
{
    public function scopeActive($query)
    {
        return $query->where('active', 1);
    }

    public function scopeByRole($query, $role)
    {
        return $query->where('role', $role);
    }
}

User::active()->byRole('admin')->get();

// 访问器：获取 name 字段时首字母大写
public function getNameAttribute($value)
{
    return ucfirst($value);
}

// 修改器：保存 email 前转为小写
public function setEmailAttribute($value)
{
    $this->attributes['email'] = strtolower($value);
}

class User extends Model
{
    public function posts()
    {
        return $this->hasMany(Post::class);
    }
}

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

$user = User::with('posts')->find(1); // 预加载避免 N+1
foreach ($user->posts as $post) {
    echo $post->title;
}

class User extends Model
{
    public function roles()
    {
        return $this->belongsToMany(Role::class);
    }
}

$user->roles()->attach($roleId);

$user->roles()->where('active', 1)->get();