Simple mySQLi select to an array - php

Question

Building from a tutorial I found online.
I m trying to select all items from the 'items' table and create an array. Not sure how this is suppose to work. This $result = $this->connection->query($q); is what is causing the problem.
<?php
//DB.class.php
class DB {
protected $db_name = 'dbname';
protected $db_user = 'user';
protected $db_pass = 'pass';
protected $db_host = 'localhost';
protected $connection;
public function connect() {
$connection = new mysqli($this->db_host, $this->db_user, $this->db_pass, $this->db_name);
// check connection
if ($connection->connect_error) {
trigger_error('Database connection failed: ' . $connection->connect_error, E_USER_ERROR);
}
}
public function resultToArray($result) {
$rows = array();
while($row = $result->fetch_assoc()) {
$rows[] = $row;
}
return $rows;
}
public function sel($table) {
$q = "SELECT * FROM $table";
$result = $this->connection->query($q);
$rows = $this->resultToArray($result);
return $rows;
$result->free();
}
}

Answer 1

make a construct function like
public $mysqli;
public function __construct()
{
$mysqli = new mysqli(DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_DATABASE);
$this->mysqli = $mysqli;
}
public function sel($table,$whr)
{
$query = "SELECT * FROM ".$table." where id='$whr'";
$result = $this->mysqli->query($query);
$total = array();
while($row = $result->fetch_assoc()){
//print_r($row);die;
$total[] = $row;
}//print_r($total);die;
return $total;
}

Answer 2

I think you should set a constructor, but if you don't want, just return an instance of it first and set your $this->connection property instead of $connection (the normal variable):
class DB {
protected $db_name = 'test';
protected $db_user = 'test';
protected $db_pass = 'test';
protected $db_host = 'localhost';
protected $connection;
public function connect() {
$this->connection = new mysqli($this->db_host, $this->db_user, $this->db_pass, $this->db_name);
// ^^ this one, not $connection
// check connection
if ($this->connection->connect_error) {
trigger_error('Database connection failed: ' . $connection->connect_error, E_USER_ERROR);
}
return $this->connection; // then return this
}
public function resultToArray($result) {
$rows = array();
while($row = $result->fetch_assoc()) {
$rows[] = $row;
}
return $rows;
}
public function sel($table) {
$q = "SELECT * FROM $table";
$result = $this->connection->query($q);
// ^ so that if you call this, you have the mysqli object
$rows = $this->resultToArray($result);
return $rows;
$result->free();
}
}
$db = new DB(); // instantite,
$db->connect(); // then connect, shouldn't have to have this if you put the connection automatically on construct
$result = $db->sel('users'); // feed a valid existing table name
echo '<pre>';
print_r($result);