<?phpinclude 'public.php';$sql="select * from user1";$rows=mysqli_query($conn,$sql);while($arr=mysqli_fetch_assoc($rows)){print_r($arr);echo '<br>'; //输出结果集内所有数据
    }
?>

<?phpheader("content-type:text/html;charset=utf8"); //utf8编码格式$servername='localhost';  //服务器地址$db_username='root';     //服务器用户名$db_password='root';    //服务器密码$db_name='zqy';        //数据库名$conn=new mysqli($servername,$db_username,$db_password,$db_name);  //连接服务器//是否连接成功 否则返回失败的原因connect_error 是$conn里面的方法if($conn->connect_error){die("连接失败:".$conn->connect_error);}//设置编码格式$conn->query("set names utf8");
?> 

function ajax(method,url,json,success,error){// 创建ajax对象实例xml=new XMLHttpRequest() || new ActiveXObject('Microsoft,XMLHTTP');//用户向客户返回的参数数据var str='';for(var attr in json){str+='&'+attr+"="+json[attr];}str=str.slice(1)// 判断请求方式 首先开启在进行发送请求if(method=='get'){xml.open('get',url+'?'+str,true);xml.send();}if(method=='post'){xml.open('post',url,true);xml.setRequestHeader("content-type","application/x-www-form-urlencoded");xml.send(str);}//监听ajax和服务器状态xml.onreadystatechange=function(){if(xml.readyState==4 && xml.status==200){success&&success(xml.responseText)}else{error&&error(xml.status)}}
}

<?phpinclude "public.php"; //引入外部文件$uname = $_REQUEST["uname"];$upwd= $_REQUEST["upwd"];//编写SQL语句$sql = "INSERT INTO `user`(uname,upwd) VALUES ('$uname','$upwd')";//执行sql语句$rows = mysqli_query($conn,$sql); //返回受影响行数if($rows){echo json_encode(array("status"=>1,"info"=>"注册成功"));}else{echo json_encode(array("status"=>0,"info"=>"失败"));}
?>

<?phpinclude "public.php";$uname = $_REQUEST["uname"];$upwd= $_REQUEST["upwd"];//编写SQL语句$sql="SELECT * FROM `user` WHERE uname='$uname'";//执行SQL语句$rows = mysqli_query($conn,$sql); //返回结果集//获取关联数组$arr = mysqli_fetch_assoc($rows);if($arr['uname']){if($arr["upwd"] == $upwd ){echo json_encode(["status"=>1,"info"=>'登录成功']);}else{echo json_encode(array("status"=>2,"info"=>"密码错误"));}}else{echo json_encode(array("status"=>0,"info"=>"用户名错误"));}?>

<?phpinclude "public.php";$uname = $_REQUEST["uname"];$upwd= $_REQUEST["upwd"];// 编写SQL语句$sql = "UPDATE user SET upwd='$upwd' WHERE uname='$uname'";// 执行sql语句返回受影响行数$rows = mysqli_query($conn,$sql);if($rows){echo json_encode(array("status"=>1,"info"=>"更改成功，祝您愉快"));}else{echo json_encode(array("status"=>0,"info"=>"用户名不存在"));}
?>

<?phpinclude "public.php";$uname = $_REQUEST["uname"];$upwd= $_REQUEST["upwd"];// 编写SQL语句$sql = "delete from user where uname = $uname";// 执行sql语句返回受影响行数$rows = mysqli_query($conn,$sql);if($rows){echo json_encode(array("status"=>1,"info"=>"删除成功，祝您愉快"));}else{echo json_encode(array("status"=>0,"info"=>"用户名不存在"));}
?>