saving multiple check-boxes as different records in php - php

Question

Am trying to save the result of multiple check-boxes as separate records. my code is not functioning. please help!
<?php
session_start();
$id = $_SESSION['user_id'];
$db = new PDO('mysql:host=localhost;dbname=idp;charset=utf8','root', '');
foreach($_POST['comp'] as $val){
$tmp['user_id'] = $id;
$tmp['comp_id'] = $val;
$vars[] = $tmp;
}
$qry = "INSERT INTO compentency_result (user_id, result) VALUES (:user_id, :comp_id)";
try
{
$sql = $db->prepare($qry);
$numRows = 0;
foreach($vars as $insert){
$numRows += $sql->execute($insert);
}
print("<p>There were {$numRows} inserted into the database!</p>");
}
catch(PDOException $e)
{
print("<p>Oops! There was an issue - this is the message: {$e->getMessage()}</p>");
}
?>
The result is showing me that nothing is added to the database.

Answer 1

To bind the parameters individually you would do this:
try
{
$sql = $db->prepare($qry);
$numRows = 0;
foreach($vars as $insert){
$sql->bindParam(':user_id', $insert['user_id'], PDO::PARAM_STR);
$sql->bindParam(':comp_id', $insert['comp_id'], PDO::PARAM_STR);
$sql->execute();
$numRows += $sql->rowCount(); // get the rows affected this way
}
echo "<p>There were {$numRows} inserted into the database!</p>";
}
In addition, I added a more proper and reliable method of getting the affected rows, using rowCount().
If you don't want to bind the elements individually you can use execute() with an array as shown in Demystifying PDO