php-为foreach()提供的参数无效
嘿,我试着使用foreach函数,我得到了这个错误…我的代码是这样的 My index.phpphp-为foreach()提供的参数无效,php,mysql,class,pdo,Php,Mysql,Class,Pdo,嘿,我试着使用foreach函数,我得到了这个错误…我的代码是这样的 My 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
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>';
}
}
require_once'core/init.php';
$user=DB::getInstance()->get('users',array('username','=','kostas');
如果(!$user->count()){
回应“无用户”;
}否则{
foreach($user->results()作为$user){
#代码。。。
echo$user->用户名“
”;
}
}
我的DB.php有这些函数
<?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 $this->_count;
}
}
?>
你能告诉我这里可能出了什么问题吗???
“我的数据库”在“用户”表中已经有一个用户名为kostas的表,因此它应该正确返回结果。请尝试为变量指定其他名称
foreach ($user->results() as $u) {
//# code...
echo $u->username, '<br>';
}
foreach($user->results()作为$u){
//#代码。。。
echo$u->用户名“
”;
}
您在这里两次使用同一个变量,这可能是问题所在吗
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 $user->username, '<br>';
}
}
代码中有“$this->\u reults”。。输入错误..传递给类get()方法的错误参数将返回一个您没有处理的布尔值false:这不是问题所在,但您应该解决它。您可能会从post中受益。这是一个愚蠢的错误$this->\u reults=$this->\u query->fetchAll(PDO::FETCH\u OBJ);正确:$this->\u results=$this->\u query->fetchAll(PDO::FETCH\u OBJ);不管怎样,谢谢你的回答。。。
$userQuery = DB::getInstance()->get('users', array('username', '=', 'kostas'));
if(!$userQuery->count()) {
echo "No user";
}else {
foreach ($userQuery->results() as $user) {
# code...
echo $user->username, '<br>';
}
}
foreach ($user->results() as $usr) {