Question

I am having a problem with mysqli. I am trying to search a database for all people who meet a category. While looping through the results, I want to create an instance of a “Person” class, passing the database connection to the class. This is where the problem starts. Here is my code.

$con = new mysqli($db_host,$db_user,$db_password,$db_name);
if (mysqli_connect_errno())
{
    die(mysqli_connect_error()); //There was an error. Print it out and die
}

$sql = "SELECT id FROM users";
$stmt = $con->prepare( $sql );
if ($stmt)
{
    $stmt->execute();
    $stmt->bind_result($id);

    while($stmt->fetch())
    {
        $person = new Person( $con );
    }
    $stmt->close();
}

If i move the $person = new Person( $con ); to just after the while loop, it successfully makes an object of the last person. It just won’t work when inside the loop. What is the reason for this?

Answer 1

According to error shown, you can’t use the same connection until previous result set is in use. In order to make it work, you can do something like this:

    $personIDs = array();
    while($stmt->fetch())
    {
        $personIDs[] = $id;
    }
    $stmt->close();

and than just go through all ids buffered into array:

foreach($personIDs as $id) {
    $person = new Person( $con );
}

Or, you can use store_results

if ($stmt)
{
    $stmt->execute();
    $stmt->bind_result($id);
    $stmt->store_results();

    while($stmt->fetch())
    {
        $person = new Person( $con );
    }
    $stmt->free_result();
    $stmt->close();
}