导出数据库

//TP5框架显示

public function index()
{
    header("content-type:text/html;charset=utf-8");
    header("content-type:application/vnd.ms-excel");
    header("content-disposition:attachment;filename=数据.xls");
    $a=Db::table('user')->select();
    $str="编号\t姓名\t性别\t年龄"."\n";
    foreach($a as $k =>$v){
        $str.=implode("\t",$v)."\n";
    }
    echo $str;
    return view("index");
}