My code does not read from mysql database - php

Question

I've tried to debug this times without success. Here is what I've tried so far
<?php
$cid= (string)$_GET['cid'];//I passed this from another page using get method
echo $cid; //My code works up to this point
$record = mysql_query("select * from questions where QType = '$cid'");
$array = array();
while($row = mysql_fetch_assoc($record))
{
$array[] = $row;
}
for($var = 0; $var<count($array);$var++)
{
echo $array[$var]['Question'].'<br>';
}
?>

Answer 1

This code will work and is a bit safer
<?php
//Connection part
$servername = "server_adress"; //It can be localhost or 127.0.0.1 or some other IP
$username = "XXXXXX"; //Username for DB
$password = "YYYYYY"; //Password for that user
$database = "ZZZZZZ"; //DB name you are connecting to
//Create a new connection
$conn_to_db = new mysqli($servername, $username, $password,$database);
// Check connection
if ($conn_to_db -> connect_error) {
die("Connection failed: " . $conn_to_db ->connect_error);
}
//Finished connection part
$cid = mysqli_real_escape_string($conn_to_db, $_GET['cid']); //Escapes special characters in a string for use in an SQL statement
$array = array();
if($stmt = $conn_to_db -> ("SELECT * FROM questions WHERE QType = ?")) {
$stmt -> bind_param("s", $cid);
$stmt -> execute();
$stmt -> bind_result($question_from_db); //Here you can put all variables you are fetching from DB
while($stmt -> fetch()){
//Iterate over rows - put your code here to fetch everything you need from DB and put in array
$array[] = array('question' => $question_from_db);
}
$stmt -> close();
}
}
//you can iterate over rows like this
foreach($array as $key => $value) {
echo $value['question'];
}
?>
Couple of things to keep in mind:
it's a good practice to avoid * (selecting everything from DB) and
put only columns you need from DB
use prepared statement which is a safer way and protects you from SQL injection
MySQL is depreciated so try to avoid it (use mysqli or PDO)
The code above you need to adjust to your needs! It will not work as copy/paste. Put your DB connection and select columns from DB you need and add variables which you fetch from DB
Keep in mind there are more ways to do this, and someone will probably give another solution.
if you are not on a production server, it's good to have some error reporting to see the errors that are happening