PDO: How can I run multiple prepared statements in a transaction? - php

Question

Using PDO, I am trying to run two prepared statements within a transaction. I only want the second prepared statement to run if the first one executes successfully and vice versa.
//Open Database Connection
$dbh = new PDO("mysql:host=$host;dbname=$dbname", $user, $pwd);
//Set Error Handling
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
//Run First Prepared Statement
$sql = 'UPDATE listers SET
first_name = :first_name,
last_name = :last_name,
address = :address,
apt = :apt,
city = :city,
state = :state,
zip_1 = :zip_1,
phone_prefix = :phone_prefix,
phone_first = :phone_first,
phone_last = :phone_last
WHERE lister_id = :lister_id';
try {
$dbh->beginTransaction();
$result = $dbh->prepare($sql);
$result->bindParam(':first_name', $_POST['first_name'], PDO::PARAM_STR);
$result->bindParam(':last_name', $_POST['last_name'], PDO::PARAM_STR);
$result->bindParam(':address', $_POST['address'], PDO::PARAM_STR);
$result->bindParam(':apt', $_POST['apt'], PDO::PARAM_STR);
$result->bindParam(':city', $_POST['city'], PDO::PARAM_STR);
$result->bindParam(':state', $_POST['state'], PDO::PARAM_STR);
$result->bindParam(':zip_1', $_POST['zip_1'], PDO::PARAM_INT);
$result->bindParam(':phone_prefix', $phone_1_prefix, PDO::PARAM_INT);
$result->bindParam(':phone_first', $phone_1_first, PDO::PARAM_INT);
$result->bindParam(':phone_last', $phone_1_last, PDO::PARAM_INT);
$result->bindParam(':lister_id', $_GET['lister_id'], PDO::PARAM_INT);
$result->execute();
//Run Second Prepared Statement
$current_date = time(); //Current Date/time in Unix format
$sql = 'INSERT INTO hidddstory_details SET
history_id = :history_id,
listing_type = "lister",
date_added = :date_added,
listing_id = :listing_id';
$result = $dbh->prepare($sql);
$result->bindParam(':history_id', $account_edited_admin, PDO::PARAM_INT);
$result->bindParam(':date_added', $current_date, PDO::PARAM_INT);
$result->bindParam(':listing_id', $row['lister_id'], PDO::PARAM_INT);
$result->execute();
$dbh->commit();
} catch(PDOException $e) {
$error = '<div id="error"><p class="error_message">The account could not be edited due to a system error. We apologize for any inconvenience.</p></div>';
$dbh->rollBack();
echo errorHandle($e);
}
When I load the page without any syntax errors, it runs the prepared statements correctly. When I purposefully add some letters to the history_details table name, as you can see above, it displays the error message relating to the incorrect table name, as it should. Unfortunately though, it doesn't rollback the first prepared statement, so when I check the listers table, it has actually updated that table, which it shouldn't.
How can I run multiple prepared statements in a transaction?

Answer 1

Examine the storage engine for the table you are trying to perform transactions on to ensure that it in fact supports transactions. As far as I know InnoDB is on the only format that currently supports transactions. Engines that do not support transactions will silently do nothing, no errors will be issued nor will any rollback be done.