PHP用mysqli来连接数据库

//设置编码格式
header("Content-type: text/html; charset=utf-8"); 
//用mysqli来连接数据库（服务器，用户名，密码，数据库名字）
$mysqli=new mysqli("localhost","root","","test");
if(mysqli_connect_errno()){
    echo "连接数据库失败：".mysqli_connect_error();
    $mysqli=null;
    exit;
}


echo "连接数据库成功！
";


//获取MySQL编码
echo $mysqli->character_set_name()."
";


//获取客户端信息
echo $mysqli->get_client_info()."
";


//执行插入和删除，更新语句
//$sql="insert into students (name,sex,age,tel) values('hello','man','25','13525654699')";
//$sql="delete from students where id>5";
$sql="UPDATE  students SET  name='xiaojia', age=19  WHERE tel='13525654699'";
//$sql = "SELECT id, uid, zt FROM dingdan"; 

//执行sql语句
$result=$mysqli->query($sql);

var_dump($result);

////////////////////////////////执行查询语句
if ($result->num_rows > 0) {  
    // 输出数据  
    while($row = $result->fetch_assoc()) {  
        echo "id: " . $row["id"]. " - uid: " . $row["uid"]. " " . $row["zt"]. "
";  
    }  
 else {  
    echo "0 结果";  
}  

//如果执行失败，则抛出错误
if(!$result){
    echo "sql语句错误
";
    echo "error:".$mysqli->error."|".$mysqli->error;
    exit;    
}


//获取影响行数
echo "影响行数：".$mysqli->affected_rows."
";
if($mysqli->affected_rows>0){
    echo "执行成功，有行数被影响！
";    
}


//获取最后一个自增长ID
echo "最后自动增长的ID：".$mysqli->insert_id;


$mysqli->close();
?>