PHP / MySQLi - 如何获取一行的值并存储在变量中？

Question

I am going through my code and I am running so many queries it is getting long. If I just want to store a single variable with a value, I have to do this:

switch($type) {
    case "next":
    if ($stmt = $mysqli->prepare("SELECT sort_order FROM user_slides WHERE user_id = ? AND sort_order > ? ORDER BY sort_order LIMIT 1")) {
        $stmt->bind_param('is', $user_id, $sortId);
        $stmt->execute();
        $stmt->bind_result($next_sort_id);
        $stmt->store_result();
        $stmt->fetch();

        return $next_sort_id;

        $stmt->close();
    }
    break;

    case "first":
    if ($stmt = $mysqli->prepare("SELECT MIN(sort_order) as max_slides FROM user_slides WHERE user_id = ?")) {
        $stmt->bind_param('i', $user_id);
        $stmt->execute();
        $stmt->bind_result($first_sort_id);
        $stmt->store_result();
        $stmt->fetch();

        return $first_sort_id;

        $stmt->close();
    }
    break;

    case "last":
    if ($stmt = $mysqli->prepare("SELECT MAX(sort_order) as max_slides FROM user_slides WHERE user_id = ?")) {
        $stmt->bind_param('i', $user_id);
        $stmt->execute();
        $stmt->bind_result($last_sort_id);
        $stmt->store_result();
        $stmt->fetch();

        return $last_sort_id;

        $stmt->close();
    }
    break;
}

There has to be an easier way to do this. Where I can just do it like this:

$first_sort_id = QUERY HERE
$last_sort_id = QUERY HERE

So it doesn't have to be so long, it can be nice and short.

Does anyone know what I need to do to accomplish that?

Answer 1

First

If you use return the statement $stmt->close(); will be never executed.

Second

Get rid of two vars, you just need one. Don't get fooled by semantic meanings.

Third

A simple reorganization could be this:

switch($type)
{
   case "next":
      $Query = "SELECT sort_order";
   break;
   case "first":
      $Query = "SELECT MIN(sort_order)";
   break;
   case "last":
      $Query = "SELECT MAX(sort_order)";
   break;
}

if ($stmt = $mysqli->prepare("$Query as max_slides FROM user_slides WHERE user_id = ?"))
{
      $stmt->bind_param('i', $user_id);
      $stmt->execute();
      $stmt->bind_result($value);
      $stmt->store_result();
      $stmt->fetch();
      $stmt->close();

      return $value;
}
else
   return NULL;