$data = [

    'username' => 'xiaohong',

    'nickname' => '小红红',

    'email'    => '12356788@qq.com',

    'phone'    => '',

    'password' => md5(''),

    'login_status'=> ,

];

$res=DB::table('admins')->insertGetId($data);

$res=DB::table('admins')->whereIn('id',[,])->delete();

$data = [

          'nickname'=> '超级管理员',

          'email'   => 'itheima@qq.com',

        ];

$res = DB::table('admins')->where('username','=','root')->update($data);    

$where=[

    ['id','>',],

    ['id','<',],

];

$res=DB::table('admins')->where('nickname');