Results are repeating in DB::getInstance - php

Question

I am new to php and I am trying to develop a class. I am connected to sqlsrv and the connection is fine. Its when I run the query the results are repeating almost like it's in a loop. I can not find the problem and I was hoping an extra pair of eyes can help. Any help is appreciated!
class DB{
private static $_instance = null;
private $_connection,
$_query,
$_error = false,
$_results,
$_count = 0;
private function __construct(){
$mssqlInfo = array( "Database"=>"db");
$mssqlServer = "server";
$this->_connection = sqlsrv_connect($mssqlServer, $mssqlInfo);
if($this->_connection === false ) {
echo '<h2>Unable to connect to database</h2><br/>';
die( print_r(sqlsrv_errors(), true));
}else{
//echo 'Connected';
}
}
public static function getInstance(){
if(!isset(self::$_instance)){
self::$_instance = new DB();
}
return self::$_instance;
}
public function query($sql, $params = array()){
$this->_error = false;
$options = array( "Scrollable" => SQLSRV_CURSOR_STATIC );
$this->_query = sqlsrv_query($this->_connection, $sql, $params,$options);
if($this->_query){
$this->_results = sqlsrv_fetch_object($this->_query);
$this->_count = sqlsrv_num_rows($this->_query);
}else{
$this->_error = true;
echo 'Error in statement execution.\n';
die( print_r( sqlsrv_errors(), 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 first(){
return $this->results()[0];
}
public function error(){
return $this->_error;
}
public function count(){
return $this->_count;
}
}
here is the instance on the index page that I am using to test my functions and to retrieve the query.
require_once 'core/init.php';
$users = DB::getInstance()->query("SELECT * FROM users");
$user = DB::getInstance()->get('users', array('username', '=', 'mike'));
if(!$user->count()){
echo 'No user';
}else{
$obj = $users->results();
foreach($obj as $users){
echo $users->username;
echo '<br/>';
}
}
I forgot to included the table.
CREATE TABLE [dbo].[users](
[id] [int] IDENTITY(1,1) NOT NULL,
[username] [varchar](20) NOT NULL,
[password] [varchar](64) NOT NULL,
[salt] [varchar](32) NOT NULL,
[name] [varchar](50) NOT NULL,
[joined] [datetime] NOT NULL,
[group] [int] NOT NULL,
CONSTRAINT [PK_users] PRIMARY KEY CLUSTERED
(
[id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

Answer 1

You fetch only one row of the results in function query() and save it to member _results:
$this->_results = sqlsrv_fetch_object($this->_query);
Then you use function results() in a while loop. results() returns an object saved in member _results which will never change. That's why you got an endless loop.
Solution for your problem:
Change
public function query($sql, $params = array()){
[...]
$this->_query = sqlsrv_query($this->_connection, $sql, $params,$options);
if($this->_query){
$this->_results = sqlsrv_fetch_object($this->_query);
$this->_count = sqlsrv_num_rows($this->_query);
[...]
to
public function query($sql, $params = array()){
[...]
$this->_query = $sql;
$this->_results = sqlsrv_query($this->_connection, $sql, $params,$options);
if($this->_query){
$this->_count = sqlsrv_num_rows($this->_query);
[...]
And change
public function results(){
return $this->_results;
}
to
public function results(){
return sqlsrv_fetch_object($this->_results);
}

Answer 2

It looks like you're setting $obj to $user->results() in your while loop, so it's always true and therefore never stops.
Just change it to a foreach().
$obj = $user->results();
foreach ($obj as $user) {
echo $user->username;
echo '<br/>';
}