Question

Note: I’m a PHP beginner which is why the code below might be bad.

Hi. I’m using this code at the moment to select 9 unique random rows and it works fine.

$quCountRows = $database->query("SELECT * FROM approved")->rowCount();
$arrRandomPictures = array();
while (count($arrRandomPictures) < 9) {
    $randNumber = mt_rand(1, $quCountRows);
    if (!in_array($randNumber, $arrRandomPictures)) {
        $arrRandomPictures[] = $randNumber;
    }
}
$quRandomPicture1 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[0]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture2 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[1]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture3 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[2]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture4 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[3]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture5 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[4]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture6 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[5]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture7 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[6]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture8 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[7]."'")->fetch(PDO::FETCH_ASSOC);
$quRandomPicture9 = $database->query("SELECT picName,picType FROM approved WHERE id='".$arrRandomPictures[8]."'")->fetch(PDO::FETCH_ASSOC);

Although it may work I’m pretty sure the same results can be obtained with less queries. Which would hopefully result in the page loading quicker.

Any suggestions?

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Here’s the better code. Thanks to Amber!

$quCountRows = $database->query("SELECT * FROM approved")->rowCount();
$arrRandomPictures = array();
while (count($arrRandomPictures) < 9) {
    $randNumber = mt_rand(1, $quCountRows);
    if (!in_array($randNumber, $arrRandomPictures)) {
        $arrRandomPictures[] = $randNumber;
    }
}
$quRandomPicture = $database->query("SELECT picName,picType FROM approved WHERE id IN (".implode(', ', $arrRandomPictures).")")->fetchAll(PDO::FETCH_ASSOC);

Answer 1

Use in instead of == and pass a list of IDs. That way you can get all of the results from one query rather than 9.