Joining a string and array elements not working - php

Question

Here is my PHP code:
$conn = new mysqli(DB_HOST, DB_USER, DB_PASSWORD);
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$statecodes = array(0=>"test1","test2");
while($i<sizeof($statecodes)) {
$ini = "users_";
$var = sprintf("%s%s", $ini, $statecodes[$i]);
print $var;
$query = "CREATE DATABASE IF NOT EXISTS" . $var;
$stmt = $mysqli->prepare($query);
/* Execute the statement */
$stmt->execute();
$i=$i+1;
/* close statement */
$stmt->close();
}
And the output i get is
users_
I want to create databases named user_test1 and user_test2

Answer 1

Try this out. You were missing a space after IF NOT EXISTS and your loop was broken due to not initializing your counter. PHP provides a lot of convenient methods for doing things like array traversal and string concatenation; looking at your code I'd guess your experience is with a much lower level language? Things like printf() come in handy for some tasks, but it's overkill when you just want to jam two strings together!
Finally, no need to prepare and execute a query if it isn't a prepared statement with placeholders. You will, however, want to sanitize your input and check the result of your query for errors.
<?php
$conn = new mysqli(DB_HOST, DB_USER, DB_PASSWORD);
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$statecodes = array("test1","test2");
foreach ($statecodes as $state) {
$var = "users_$state";
// remove dangerous characters!
$var = preg_replace("/[^\w]/", "", $var);
$query = "CREATE DATABASE IF NOT EXISTS $var";
$result = $conn->query($query);
if (!$result) {
//do something!
}
}