public function index()
{
//插入
$res=Db::name("user")->insert([
"id"=>"12",
"name"=>"beijing",
"number"=>1
]);
//改
$res=Db::name("user")->where("id",12)->update(["name"=>"thinkphp"]);
//查
$res=Db::name("user")->select();
//删除
$res=Db::name("user")->where("id",12)->delete();
return $res;
}