Issue with simple SQL statement / PHP function not working - php

Question

I have a simple function to write into my database. This is the error I am getting.
This is the error I am getting
Notice: Trying to get property of non-object in /var/sites/q/quasisquest.uk/public_html/KeepScore/MySQLDao.php on line 92 Fatal error: Uncaught exception 'Exception' in /var/sites/q/quasisquest.uk/public_html/KeepScore/MySQLDao.php:92 Stack trace: #0 /var/sites/q/quasisquest.uk/public_html/KeepScore/createCommunity.php(26): MySQLDao->createCommunity('radowns82#gmail...', 'YGHFYG', 'Endcliffe') #1 {main} thrown in /var/sites/q/quasisquest.uk/public_html/KeepScore/MySQLDao.php on line 92
This is the initial PHP script that calls it:
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
require("Conn.php");
require("MySQLDao.php");
$email = htmlentities($_POST["email"]);
$code = htmlentities($_POST["code"]);
$communityname = htmlentities($_POST["communityname"]);
$dao = new MySQLDao();
$dao -> openConnection();
$result = $dao -> createCommunity($email, $code, $communityname);
$dao->closeConnection();
?>
This is MySQLDao.php
<?php
class MySQLDao{
var $dbhost = null;
var $dbuser = null;
var $dbpass = null;
var $conn = null;
var $dbname = null;
var $result = null;
public function __construct(){
$this->dbhost = Conn::$dbhost;
$this->dbuser = Conn::$dbuser;
$this->dbpass = Conn::$dbpass;
$this->dbname = Conn::$dbname;
}
public function openConnection()
{
$this->conn = new mysqli($this->dbhost, $this->dbuser, $this->dbpass, $this->dbname);
if (mysqli_connect_errno())
echo new Exception("Could not establish connection with database");
}
public function getConnection()
{
echo ("2");
return $this->conn;
}
public function closeConnection()
{
if($this->conn!=null)
$this->conn->close();
}
public function getUserDetails($email)
{
$returnValue = array();
$sql = "select * from users where user_email='".$email."'";
$result = $this->conn->query($sql);
if($result != null && (mysqli_num_rows($result) >= 1)){
$row = $result -> fetch_array(MYSQLI_ASSOC);
if(!empty($row)){
$returnValue = $row;
}
}
return $returnValue;
}
public function getUserDetailsWithPassword($email, $userPassword)
{
$returnValue = array();
$sql = "select id, user_email, user_name from users where user_email = '".$email."' and user_password = '".$userPassword."'";
$result = $this->conn->query($sql);
if($result != null && (mysqli_num_rows($result) >= 1 )){
$row = $result -> fetch_array(MYSQLI_ASSOC);
if(!empty($row)){
$returnValue = $row;
}
}
return $returnValue;
}
public function registerUser($email, $password, $username)
{
$sql = "insert into users set user_email=?,user_password=?,user_name=?";
$statement = $this->conn->prepare($sql);
if(!$statement)
throw new Exception($statement->error);
$statement->bind_param("sss", $email, $password, $username);
$returnValue = $statement->execute();
return $returnValue;
}
public function createCommunity($email, $code, $communityname)
{
$sql = "insert into communities set email=?,code=?,communityname=?";
$statement = $this->conn->prepare($sql);
if(!$statement){
throw new Exception($statement->error);
}
$statement->bind_param("sss", $email, $code, $communityname);
$returnValue = $statement->execute();
return $returnValue;
}
}
?>
That 'communities' table also has an 'id' column (1st column) which I am not posting to as I thought it would auto-populate and increment... maybe this is where I am going wrong?

Answer 1

If the connection fails first you need to know why so show the actual database error. and second, there is very little point in continuing the scripts execution without a connection to the database.
So can I suggest this change to your openConnection() method
Also if you think there is any chance of something wrong in the MSYQLI code these 4 lines will basically ensure you get told about any errors, while you are developing, specially if you are developing on a live server with ERROR REPORTING turned off.
<?php
ini_set('display_errors', 1);
ini_set('log_errors',1);
error_reporting(E_ALL);
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
public function openConnection()
{
$this->conn = new mysqli($this->dbhost, $this->dbuser,
$this->dbpass, $this->dbname
);
if ($mysqli->connect_error) {
echo 'Connect Error: ' . $mysqli->connect_errno . ' - '
. $mysqli->connect_error;
exit;
}
}