Looking for an alternative to get_result() [duplicate] - php

Question

I am totally confused by mySQLi. Although I have been using procedural mysql calls for years, I want to get used to making prepared statements for the db security/mySQL injection protection it offers. I am trying to write a simple select statement (yes I know making a procedural call for this offers performance enhancement). When run, I get all the echoes until I hit the $result = $stmt->get_result(); component. It all seems fairly straightforward to me, but I am at a loss after hours of reading manuals on mySQLi. Any ideas why this would be failing?
*note: this is a test environment and while no sanitizing/escaping of characters is taking place, I am only passing valid content into the variables $username and $email. And also, I have looked all over SO to find the solution to my issue.
function checkUsernameEmailAvailability($username, $email) {
//Instantiate mysqli connection
#$mysqli = new mysqli(C_HOST,C_USER,C_PASS,C_BASE) or die("Failed to connect to MySQL database...");
if (!$mysqli)
{
echo 'Error: Could not connect to database. Please try again later...';
exit;
} else {
echo 'mysqli created';
}
/* Create a prepared statement */
if($stmt = $mysqli -> prepare("SELECT username,email FROM tb_users WHERE username=? OR email=?")) {
echo '<br />MYSQLi: ';
/* Bind parameters s - string, b - boolean, i - int, etc */
$stmt -> bind_param("ss", $username, $email);
echo '<br />paramsBound...';
/* Execute it */
$stmt -> execute();
echo '<br />Executed';
$result = $stmt->get_result();
echo '<br />Result acquired';
/* now you can fetch the results into an array - NICE */
$myrow = $result->fetch_assoc();
echo '<br />Fetched';
/* Close statement */
/$stmt -> close();
echo '<br />Done mysqli';
}
}
Also, do I have to instantiate a mysqli every time I call a function? I'm assuming they're not persistent db connects like in procedural mysql. Yes, I am aware this is a scope issue, and no I have not been able to understand the scoping of this class variable. When I declared it outside of the function, it was not available when I came into the function.
UPDATE
if I change line 12 from:
if($stmt = $mysqli -> prepare("SELECT username,email FROM tb_users WHERE username=? OR email=?")) {
to:
$stmt = $mysqli->stmt_init();
if($stmt = $mysqli -> prepare("SELECT username,email FROM tb_users WHERE username=? OR email=?")) {
if(!stmt) echo 'Statement prepared'; else echo 'Statement NOT prepared';
I get Statement NOT prepared. Now I'm even more confused....
UPDATE:
I contacted my hosting provider and apparently mySQLi is supported, and the mysqlnd driver is present. Perhaps there is a way to simply test this? Although they usually have given me pretty knowledgeable answers in the past.
UPDATE...AGAIN: I checked my server capabilities myself and discovered, while mysqli and PDO are present, mysqlnd is not. Thusly, I understand why get_result() will not work (mysqlnd required I think), I still don't understand why the prepared statement itself will not work.

Answer 1

Through some checking, even though mysqli is installed on my host, apparently the mysqlnd driver is not present. Therefore, get_result() can not be used(php manual defines get_result as mysqlnd dependent), and instead extra coding would need to be done to handle my result the way I would like.
Therefore, I decided to try and learn how PDO works, and within minutes, voila!!!
Replaced the above code with this:
function checkUsernameEmailAvailability($username, $email) {
echo 'pdo about to be created';
$dsn = 'mysql:dbname='.C_BASE.';host='.C_HOST;
$user = C_USER;
$password = C_PASS;
try {
$dbh = new PDO($dsn, $user, $password);
} catch (PDOException $e) {
echo 'Connection failed: ' . $e->getMessage();
}
$params = array(':username' => $username, ':email' => $email);
try{
$sth = $dbh->prepare('SELECT username,email FROM tb_users WHERE username = :username OR email = :email ');
} catch(PDOException $e) {
echo 'Prepare failed: ' . $e->getMessage();
}
try{
$sth->execute($params);
} catch(PDOException $e) {
echo 'Execute failed: ' . $e->getMessage();
}
$result = $sth->fetch(PDO::FETCH_ASSOC);
print_r($result);
}
As much error checking as I could think of, and no problems at all first crack at it!
Final Code
function checkUsernameEmailAvailability($username, $email) {
$dsn = 'mysql:dbname='.C_BASE.';host='.C_HOST;
$user = C_USER;
$password = C_PASS;
new PDO($dsn, $user, $password);
$params = array(':username' => $username, ':email' => $email);
$sth = $dbh->prepare('SELECT username,email FROM tb_users WHERE username = :username OR email = :email ');
$sth->execute($params);
$result = $sth->fetch(PDO::FETCH_ASSOC);
print_r($result);
}

Answer 2

mysqli_stmt :: get_result is Available only with mysqlnd package. remove php5-mysql package and install php5-mysqlnd instead