嘿,我尝试使用foreach函数,我得到了这个错误...我的代码是这样的。
我的index.php
require_once 'core/init.php';
$user = DB::getInstance()->get('users', array('username', '=', 'kostas'));
if(!$user->count()) {
echo "No user";
}else {
foreach ($user->results() as $user) {
# code...
echo $user->username, '<br>';
}
}
我的DB.php有这些功能
<?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, $param);
$x++;
}
}
if($this->_query->execute()){
$this->_reults = $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 $this->_count;
}
}
?>
你可以告诉我这里可能出了什么问题吗?
我的数据库已经在users表中有一个用户名为kostas的表,因此它应该返回结果corectly。
答案 0 :(得分:1)
为变量尝试不同的名称
foreach ($user->results() as $u) {
//# code...
echo $u->username, '<br>';
}
答案 1 :(得分:1)
foreach ($user->results() as $user) {
你在这里使用相同的变量两次,这可能是问题吗?
您可以重命名其中一个变量。在这里,我将第一个$user
重命名为$userQuery
,因为我认为这更清楚:
$userQuery = DB::getInstance()->get('users', array('username', '=', 'kostas'));
if(!$userQuery->count()) {
echo "No user";
}else {
foreach ($userQuery->results() as $user) {
# code...
echo $user->username, '<br>';
}
}
或者您可以在foreach中重命名变量:
foreach ($user->results() as $usr) {