Home >Backend Development >PHP Tutorial >刚转学php，请大家帮我写段数据库查询类的代码
刚转学php，请大家帮我写段数据库查询类的代码
- WBOYOriginal
- 2016-06-23 14:28:38873browse
大家好，本人初转php，想建立一个pdo连接的数据库操作类，但是不知道php的调用方法，请大家指点下。
类文件coon.php内容：
<?phpclass my_sql{public $dbh;public $sth;//连接数据库public function sql_open(){ $host='localhost'; //数据库主机名 $dbName='lif2'; //使用的数据库 $user='root'; //数据库连接用户名 $pass='123456'; //对应的密码 $dsn='mysql:host='.$host.';dbname='.$dbName; try { $dbh = new PDO($dsn, $user, $pass); $dbh->query("SET NAMES UTF8"); $dbh->exec("SET NAMES UTF8"); } catch(Exception $e) { echo 'data error: '.$e->getMessage(); }}//关闭数据库连接public function sql_close(){ $dbh=null;}//查询数据库public function my_query($sql){ $this->sql_open(); //$this->sth = $this->dbh->query($sql); //$result = $this->sth->fetchAll(); //return $result; 这里面怎么写才能返回数据？ }}?> 页面调用代码：
<body><?phpinclude 'conn.php';$mysql = new my_sql;foreach ($mysql->my_query('SELECT * FROM user_type order by user_id') as $row){//这里循环输出查询内容}$mysql->sql_close();?></body> 望详细指点下，实在弄不明白，用asp或asp.net的函数调用方法全不行，我想写一个查询，插入，更新和删除数据的通用函数，外部只要带入sql语句就可以执行的那种。
回复讨论(解决方案)
1楼围观。等大神解答！
$this->dbh = new PDO($dsn, $user, $pass);
你的my_query看上去没错，将注释的那几行打开。先试试看。
终于搞定了，看了网上众多代码，测试失败了无数次，结果是弄出来了，插入，删除，更新的通用类，请大神指点下这样做有没有什么弊端，会不会影响性能等。下一步研究下那个参数化，据说可以防止sql注入。
conn.php内容：
<?php//数据库操作类class my_sql{public $user='root'; //数据库连接用户名public $pass='123456'; //对应的密码public $dsn='mysql:host=localhost;dbname=lif2';//查询数据库返回结果public function sql_select($sql){ try { $dbh = new PDO($this->dsn, $this->user,$this->pass); $dbh->query("SET NAMES UTF8"); return $dbh->query($sql); $dbh=null; } catch(Exception $e) { echo 'error: '.$e->getMessage(); }}//操作单条数据(更新/删除/插入)，无返回结果public function sql_one($sql){ try { $dbh = new PDO($this->dsn, $this->user,$this->pass); $dbh->exec("SET NAMES UTF8"); $dbh->exec($sql); $dbh=null; } catch(Exception $e) { echo 'error: '.$e->getMessage(); }}//操作多条数据（更新/删除），无返回结果public function sql_more($sql,$str){ try { $dbh = new PDO($this->dsn, $this->user,$this->pass); $dbh->exec("SET NAMES UTF8"); foreach($str as $arrs) { $dbh->exec($sql.$arrs); } $dbh=null; } catch(Exception $e) { echo 'error: '.$e->getMessage(); } }}?> 页面调用函数：
include 'conn.php';$mysql = new my_sql;//操作单挑数据$mysql->sql_one("DELETE FROM `user_type` WHERE `user_id` = ".$_REQUEST['id']."");//读取内容$aa=$mysql->sql_select('SELECT * FROM user_type order by user_id'); foreach ($aa as $row) {//输出内容echo '<tr>';echo '<td>'.$row['user_id'].'</td><td>'.$row['user_name'].'</td><td>'.$row['user_real_name'].'</td><td>'.$row['user_sex'].'</td><td>'.$row['user_tel'].'</td><td>'.$row['user_qq'].'</td><td>'.$row['user_address'].'</td><td>'.$row['user_email'].'</td><td><a href="?action=del&id='.$row['user_id'].'" title="删除">删除</a></td><td><input name="delAll[]" class="c" type="checkbox" value="'.$row['user_id'].'" /></td>';echo '</tr>';}//操作多条数据$id=$_POST['delAll'];if(isset($id)){$mysql->sql_more("DELETE FROM `user_type` WHERE `user_id` = ",$id);} 上面的操作方法和思路还是沿袭了asp.net开发的习惯，不知道在php开发上实用不，望大神指点一下。
你现在这个不能防注入，防注入需要用PDO::prepare
<?php/* Execute a prepared statement by passing an array of values */$sth = $dbh->prepare('SELECT name, colour, calories FROM fruit WHERE calories < ? AND colour = ?');$sth->execute(array(150, 'red'));$red = $sth->fetchAll();$sth->execute(array(175, 'yellow'));$yellow = $sth->fetchAll();?> 你现在这个不能防注入，防注入需要用PDO::prepare
<?php/* Execute a prepared statement by passing an array of values */$sth = $dbh->prepare('SELECT name, colour, calories FROM fruit WHERE calories < ? AND colour = ?');$sth->execute(array(150, 'red'));$red = $sth->fetchAll();$sth->execute(array(175, 'yellow'));$yellow = $sth->fetchAll();?> 你说的这个方法我已经会弄了，参数化查询
Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Previous article：已给出相应js判断代码，如何用js或者php判断电脑是否登录qq并获得相应qq号Next article：php paypal ipn