PDO prepared statements for INSERT and ON DUPLICATE KEY UPDATE with named placeholders

Question

I\'d like to switch PDO INSERT and UPDATE prepared statements to INSERT and ON DUPLICATE KEY UPDATE since I think it\'ll be a lot more efficient than what I\'m currently doi

Answer 1

Your ON DUPLICATE KEY syntax is not correct.

$stmt = $conn->prepare('INSERT INTO customer_info (user_id, fname, lname) VALUES(:user_id, :fname, :lname)
    ON DUPLICATE KEY UPDATE fname= :fname2, lname= :lname2');

$stmt->bindParam(':user_id', $user_id);  
$stmt->bindParam(':fname', $_POST['fname'], PDO::PARAM_STR);
$stmt->bindParam(':lname', $_POST['lname'], PDO::PARAM_STR);      
$stmt->bindParam(':fname2', $_POST['fname'], PDO::PARAM_STR);
$stmt->bindParam(':lname2', $_POST['lname'], PDO::PARAM_STR);      

You don't need to put the table name or SET in the ON DUPLICATE KEY clause, and you don't need a WHERE clause (it always updates the record with the duplicate key).

See http://dev.mysql.com/doc/refman/5.5/en/insert-on-duplicate.html

You also had a PHP syntax error: you split the query up into two strings.

UPDATE:

To bind multiple parameters:

function bindMultiple($stmt, $params, &$variable, $type) {
  foreach ($params as $param) {
    $stmt->bindParam($param, $variable, $type);
  }
}

Then call it:

bindMultiple($stmt, array(':fname', ':fname2'), $_POST['fname'], PDO::PARAM_STR);