PHP OOP与数据库有关的问题 [英] PHP OOP issue with database
问题描述
我正在使用DB类中的get()函数从数据库中查询用户名.即使数据库中存在用户,它也始终返回"No users". 这是我的DB.php
I am querying usernames from database using the get() function in the DB class.. its always returning 'No users' even if there are users existing in the database.. here is my DB.php
<?php
class DB{
private static $_instance = null;
private $_pdo,
$_query,
$_error = false,
$_results,
$_count = 0;
private function __construct(){
try {
$this->_pdo = new PDO('mysql:host=' . Config::get('mysql/host') . ';dbname='. Config::get('mysql/db'), Config::get('mysql/username'), Config::get('mysql/password'));
} catch (PDOException $e) {
die($e->getMessage());
}
}
public static function getInstance() {
if (!isset(self::$_instance)) {
self::$_instance = new DB();
}
return self::$_instance;
}
public function query($sql, $params = array()) {
$this->_error = false;
if($this->_query = $this->_pdo->prepare($sql)) {
$x = 1;
if (count($params)) {
foreach ($params as $param) {
$this->_query->bindValue($x, $params);
$x++;
}
}
if ($this->_query->execute()) {
$this->_results = $this->_query->fetchAll(PDO::FETCH_OBJ);
$this->_count = $this->_query->rowCount();
} else {
$this->_error = true;
}
}
return $this;
}
public function action($action, $table, $where = array()) {
if (count($where) === 3) {
$operators = array('=','>','<','>=','<=');
$field = $where[0];
$operator = $where[1];
$value = $where[2];
if (in_array($operator, $operators)) {
$sql = "{$action} FROM {$table} WHERE {$field} {$operator} ?";
if(!$this->query($sql, array($value))->error()){
return $this;
}
}
}
return false;
}
public function get($table, $where) {
return $this->action('SELECT *', $table, $where);
}
public function delete($table, $where) {
return $this->action('DELETE', $table, $where);
}
public function results(){
return $this->_results;
}
public function error(){
return $this->_error;
}
public function count(){
return $this->_count;
}
}
index.php
index.php
<?php
require_once 'core/init.php';
$user = DB::getInstance();
$user->get('users', array('username', '=', 'alex'));
if(!$user->count()) {
echo 'No user';
} else {
foreach ($user->results() as $user) {
echo $user->username, '<br>';
}
}
即使使用此数据库,即使数据库中已有用户,也会获得无用户"信息.
Am getting 'No user' even if there is existing user in the the DB if I use this..
$ user = DB :: getInstance()-> get('users',array('username','=','alex'));
$user = DB::getInstance()->get('users', array('username', '=', 'alex'));
但是如果我将get()替换为query(),它将返回正确的用户名(包括'alex')
but it is returning correct usernames(including 'alex') if I replace get() with query()
$ user = DB :: getInstance()-> query("SELECT * FROM users");
$user = DB::getInstance()->query("SELECT * FROM users");
推荐答案
在绑定时的查询功能中,您可以这样做:
In your query function when binding you do:
foreach ($params as $param) {
$this->_query->bindValue($x, $params);
$x++;
}
您要绑定$params
,这是一个数组,而不是值.将$params
更改为$param
(单数),可能会起作用.
You are binding $params
which is an array, not the value. Change $params
to $param
(singular) and it will likely work.
这篇关于PHP OOP与数据库有关的问题的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!