// Path:app/Http/Controllers/Auth/RegisterController.php
protected function validator(array $data)
{
 return Validator::make($data, [
 'name' => ['required', 'string', 'max:255'],
 'email' => ['required', 'string', 'email', 'max:255', 'unique:users'],
 'password' => ['required', 'string', 'min:8', 'confirmed'],
 ]);
}

// Path:vendor/laravel/framework/src/Illuminate/Foundation/Auth/AuthenticatesUsers.php
public function username()
{
 return 'email';
}
// 当然可以修改验证字段（看过文档的都知道），注意：登录验证字段必须是在表里面唯一的。

public function up()
{
 Schema::create('users', function (Blueprint $table) {
 $table->bigIncrements('id');
 $table->string('name');
 $table->string('email'); // 去掉原来的unique
 $table->string('identity'); // 增加的字段
 $table->timestamp('email_verified_at')->nullable();
 $table->string('password');
 $table->rememberToken();
 $table->timestamps();
 });
}

// Path: app/Http/Controllers/Auth/RegisterController.php
protected function create(array $data)
{
 return User::create([
 'name' => $data['name'],
 'email' => $data['email'],
 'password' => Hash::make($data['password']),
 'identity' => 'pcsoft', // 模拟用户注册时，插入身份字段值
 ]);
}

protected function validator(array $data)
{
 return Validator::make($data, [
 'name' => ['required', 'string', 'max:255'],
 'email' => ['required', 'string', 'email', 'max:255', Rule::unique('users')->where(function ($query) {
  $query->where('identity', '=', 'onlinedown');
 })], // 这句话的意思：按照什么条件对 users 表中的 email 去重，我们需要按照身份字段等于我们访问的域名对 email 去重，
 'password' => ['required', 'string', 'min:8', 'confirmed'],
 ]);
}

// Path:app/Http/Controllers/Auth/LoginController.php
protected function credentials(Request $request)
{
 $request->merge(['identity' => Controller::getWebPrefix()]);
 return $request->only($this->username(), 'password', 'identity');
}