"Execute Array" problem from Database PHP - php

Question

As I'm a beginner, I have a problem with executing an array from the database.
My code:
$operation_id = (int)$_GET["operation"];
$operation_query = $db_link->prepare('SELECT * FROM `shop_users_accounting` WHERE `id` = ? AND `active` = 0 AND `user_id` = ?;');
$operation_query->execute( array($operation_id, $user_id) );
$operation = $operation_query->fetch();
if($operation == false)
{
$answer = array();
$answer["result"] = false;
$answer["code"] = 2;
exit(json_encode($answer));
}
For now, I can echo $operation_id and $user_id without any problem
but in shop_users_accounting table I have more columns, like pay_orders and amount
I have tried do like this $operation_query->execute( array($operation_id, $user_id, $pay_orders) ); but then IF function get executed and I get false
I have tried $operation_query = $db_link->prepare('SELECT * FROM `shop_users_accounting` WHERE `id` = ? AND `active` = 0 AND `user_id` = ? AND `pay_orders` = ?;'); and the result is the same, IF function get executed and I get false
The question is, what I'm doing wrong, and how I can get pay_orders and amount from DB without getting False

Answer 1

First I'd define the connection adding the request to return the error from mysql:
$pdo = new PDO('mysql:host=127.0.0.1;dbname=mydbname', $db_user, $db_pass, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
You see the last array()? It tells mysql to return the errors.
Then I'd put everything in a try catch block so that I can handle the errors:
try{
$operation_query = $db_link->prepare('SELECT * FROM `shop_users_accounting` WHERE `id` = ? AND `active` = 0 AND `user_id` = ?;');
$operation_query->execute( array($operation_id, $user_id) );
$operation = $operation_query->fetch();
}
catch (PDOException $e) {
echo $e->getMessage();
}
So the try block will be always executed. The catch one will be executed only if there is an error and will just echo the error message. What you will do is to put inside the catch block your logic if the query fails, after the catch block your logic if your query is successfull.
The error you are getting is obscure with your code but is probably due to a value that you pass incorrectly to the query (value of the array element). There is no strict error on the syntax you use to pass the array to the query (what you call execute the array).
I'd also suggest to use named parameters in the query and bindParams() to have a more readible code with many parameters. See here for more details on how to build prepared statements.