如何通过查询获取数据，以便使用面向对象的类创建编辑函数？
如何通过查询获取数据，以便使用面向对象的类创建编辑函数？
提问于 2018-07-29 06:51:02
请帮帮我。我不知所措！我正在创建一个博客网站，管理员可以编辑和删除他们的帖子。但是，当我传递查询时：
Fatal error: Uncaught Error: Call to a member function query()
on null in C:\xampp\htdocs\tp02\TP2PHP\Posting.class.php:22
Stack trace:
'#0' C:\xampp\htdocs\tp02\TP2PHP\editardelete.php(15):
Posting->getData('SELECT * FROM b...')
'#1' {main} thrown in
C:\xampp\htdocs\tp02\TP2PHP\Posting.class.php on line 22加上一些未定义的索引。
Notice: Undefined index: titulo in C:\xampp\htdocs\tp02\TP2PHP\editardelete.php on line 10
Notice: Undefined index: contenido in C:\xampp\htdocs\tp02\TP2PHP\editardelete.php on line 11
Notice: Undefined property: Posting::$conn in C:\xampp\htdocs\tp02\TP2PHP\Posting.class.php on line 22我猜是我的关系。请帮帮忙谢谢Posting.class.php
<?php
require_once 'conexion.php';
require_once 'BaseDato.class.php';
require_once 'Admin.class.php';
class Posting extends Connectdb {
public $titulo;
public $contenido;
public function __construct($titulo,$contenido) {
$this->titulo = $titulo;
$this->contenido = $contenido;
}
public function getData($query) {
$result = $this->conn->query($query);
if ($result == false) {
return false;
}
$rows = array();
while ($row = $result->fetch_assoc()) {
$rows[] = $row;
}
return $rows;
}
public function execute($query) {
$result = $this->conn->query($query);
if ($result == false) {
echo 'Error: cannot execute the command';
return false;
} else {
return true;
}
}
public function delete($id, $table) {
$query = "DELETE FROM blogtp_1 WHERE id = $id";
$result = $this->conn->query($query);
if ($result == false) {
echo 'Error: cannot delete id ' . $id . ' from table ' . $table;
return false;
} else {
return true;
}
}
/*public function escape_string($value)
{
return $this->conn->real_escape_string($value);
} */
}
?>这是另一个名为editardelete.php的页面：
<?php
// including the database connection file
require_once 'conexion.php';
include 'BaseDato.class.php';
include 'Posting.class.php';
//datos de la conexion
$conexion = mysqli_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
session_start();
$titulo = $_POST['titulo'];
$contenido = $_POST['contenido'];
$posting = new Posting($titulo,$contenido);
//fetching data in descending order (lastest entry first)
$query = "SELECT * FROM blogtp_1 ORDER BY id DESC";
$result = $posting->getData($query);
//echo '<pre>'; print_r($result); exit;
?>
<html>
<head>
<title>Homepage</title>
</head>
<body>
<table width='80%' border=0>
<tr bgcolor='#CCCCCC'>
<td>titulo</td>
<td>contenido</td>
</tr>
<?php
foreach ($result as $key => $res) {
//while($res = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>".$res['titulo_del_post']."</td>";
echo "<td>".$res['contenido_del_post']."</td>";
echo "<td><a href=\"editar.php?id=$res[id]\">Editar</a> </td>";
}
?>
</table>
</body>
</html>这是我的connection类：
<?php
class Connectdb{
private $host;
private $user;
private $pass;
private $db;
protected function connect(){
$this->host = "localhost";
$this->user = "root";
$this->pass = "";
$this->db = "blog";
$conn = mysqli_connect($this->host, $this->user, $this->pass, $this->db);
return $conn;
}
}
?>回答 1
Stack Overflow用户
回答已采纳
发布于 2018-07-29 07:28:07
首先，我们必须重组你的代码。您的连接类。
<?php
// error class just incase an error occured when trying to connect
class __errorClass
{
public function __call($meth, $args)
{
echo $meth . '() failed! Database connection error!';
}
}
class Connectdb{
private $host = "localhost";
private $user = "root";
private $pass = "";
private $db = "blog";
public function connect()
{
$conn = mysqli_connect($this->host, $this->user, $this->pass, $this->db);
if ($conn->errorCode == 0)
{
return $conn;
}
else
{
return new __errorClass();
}
}
}
?>接下来是你的Next类。
<?php
require_once 'conexion.php';
require_once 'BaseDato.class.php';
require_once 'Admin.class.php';
class Posting{
public $titulo;
public $contenido;
private $conn;
public function __construct($titulo,$contenido) {
$this->titulo = $titulo;
$this->contenido = $contenido;
$db = new Connectdb();
$this->conn = $db->connect();
}
public function getData($query)
{
$result = $this->conn->query($query);
if ($result == false) {
return false;
}
$rows = array();
while ($row = $result->fetch_assoc()) {
$rows[] = $row;
}
return $rows;
}
public function execute($query)
{
$result = $this->conn->query($query);
if ($result == false) {
echo 'Error: cannot execute the command';
return false;
} else {
return true;
}
}
public function delete($id, $table)
{
$query = "DELETE FROM blogtp_1 WHERE id = $id";
$result = $this->conn->query($query);
if ($result == false) {
echo 'Error: cannot delete id ' . $id . ' from table ' . $table;
return false;
} else {
return true;
}
}
/*public function escape_string($value)
{
return $this->conn->real_escape_string($value);
} */
}
?>最后在您的editardelete.php文件中。
<?php
// should keep session here!
session_start();
include 'BaseDato.class.php';
include 'Posting.class.php';
// for a quick check you can use this function
// would check for titulo in GET, POST and SESSION
function is_set($name)
{
if (isset($_POST[$name]))
{
return $_POST[$name];
}
elseif (isset($_GET[$name]))
{
return $_GET[$name];
}
elseif (isset($_SESSION[$name]))
{
return $_SESSION[$name];
}
else
{
return false;
}
}
// you have to check if titulo and contenido is set
// this would reduce error level to zero!
$result = [];
if ( is_set('titulo') && is_set('contenido'))
{
$titulo = is_set('titulo');
$contenido = is_set('contenido');
$posting = new Posting($titulo,$contenido);
//fetching data in descending order (lastest entry first)
$query = "SELECT * FROM blogtp_1 ORDER BY id DESC";
$result = $posting->getData($query);
//echo '<pre>'; print_r($result); exit;
}
?>
<html>
<head>
<title>Homepage</title>
</head>
<body>
<table width='80%' border=0>
<tr bgcolor='#CCCCCC'>
<td>titulo</td>
<td>contenido</td>
</tr>
<?php
if (count($result) > 0)
{
foreach ($result as $key => $res) {
echo "<tr>";
echo "<td>".$res['titulo_del_post']."</td>";
echo "<td>".$res['contenido_del_post']."</td>";
echo "<td><a href=\"editar.php?id={$res['id']}\">Editar</a> </td>";
}
}
?>
</table>
</body>
</html>我希望这能帮到你。编码快乐，维多利亚！
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/51575847
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