每页只有一个SQL动态下拉列表可用吗？

Question

I have a webpage (in php) where the first section of PHP code gets the relevant records.

<?php
    session_start();

    require_once('Connections/default.php');

    if (isset($_POST['command'])){
        $_SESSION['Username'] = '';
        $_SESSION['Password'] = '';
        session_destroy();
    } else {
    }

    if (is_null($_POST['Username'])){
    } else {
        $_SESSION['Username'] = $_POST['Username'];
    }

    if (is_null($_POST['Password'])){
    } else {
        $_SESSION['Password'] = md5($_POST['Password']);
    }

    $sql = "SELECT * FROM Users WHERE Username LIKE '".$_SESSION['Username']."'     AND Password LIKE '".$_SESSION['Password']."'";
    $newdefectquery = "SELECT * FROM Defects WHERE Defect_Status LIKE 'New'";
    $selectallusers = "SELECT * FROM Users";

    $result = $conn->query($sql);
    $defects_new = $conn->query($newdefectquery);
    $allusers = $conn->query($selectallusers);
?>

This section of the page works correctly and pulls the results (I can see other data on the page.) I then have the following section of code, which contains a drop down menu of all the site's users (So I can assign defects to each user), but only one of the dynamic drop down menus works? It displays every user. (Where I have more than 1 defect, I would like to be able to assign any of them.)

<?php if ($defects_new->num_rows > 0){
    while ($defect = $defects_new->fetch_assoc()){ ?>
        <table border="1" width="90%">
            <tr>
                <td colspan="2">
                    <h2 style="margin:0px; font-size:25px; line-height:25px;">#<?php echo $defect['Defect_ID'] ?> - <?php echo $defect['Title'] ?> - <?php echo $defect['Found_By'] ?></h2>
                </td>
            </tr>
            <tr>
                <td width="80%">
                    <?php echo $defect['Information'] ?>
                    <br />
                    <br />
                </td>
                <td>
                    <form name="assign<?php echo  $defect['Defect_ID'] ?>" method="post" action="index.php">
                        <select name="Owner">
                        <?php while ($users = $allusers->fetch_assoc()){ ?>
                            <option value="<?php echo $users['Username']?>"><?php echo $users['Username'] ?></option>
                        <?php } ?>
                        </select>
                    </form>
                </td>
                </tr>
            </table>
            <br />
            <br />
<?php } 
} else {
    echo "There are no new defects. Good job! :)";
}
?>

Here's a picture of what I see. (I've expanded the working drop down)

The second drop down does not expand. It also does not show any options on inspect element.

Please help. Thanks.

Answer 1

<?php if ($defects_new->num_rows > 0){

$users = $allusers->fetch_assoc();

while ($defect = $defects_new->fetch_assoc()){ ?>
    <table border="1" width="90%">
        <tr>
            <td colspan="2">
                <h2 style="margin:0px; font-size:25px; line-height:25px;">#<?php echo $defect['Defect_ID'] ?> - <?php echo $defect['Title'] ?> - <?php echo $defect['Found_By'] ?></h2>
            </td>
        </tr>
        <tr>
            <td width="80%">
                <?php echo $defect['Information'] ?>
                <br />
                <br />
            </td>
            <td>
                <form name="assign<?php echo  $defect['Defect_ID'] ?>" method="post" action="index.php">
                    <select name="Owner">
                    <?php foreach($users as $user){ ?>
                        <option value="<?php echo $user['Username']?>"><?php echo $user['Username'] ?></option>
                    <?php } ?>
                    </select>
                </form>
            </td>
            </tr>
        </table>
        <br />
        <br />
<?php } 
} else {
    echo "There are no new defects. Good job! :)";
}
 ?>

Answer 2

remove user query execution part from first code part:

<?php
    session_start();

    require_once('Connections/default.php');

    if (isset($_POST['command'])){
        $_SESSION['Username'] = '';
        $_SESSION['Password'] = '';
        session_destroy();
    } else {
    }

    if (is_null($_POST['Username'])){
    } else {
        $_SESSION['Username'] = $_POST['Username'];
    }

    if (is_null($_POST['Password'])){
    } else {
        $_SESSION['Password'] = md5($_POST['Password']);
    }

    $sql = "SELECT * FROM Users WHERE Username LIKE '".$_SESSION['Username']."'     AND Password LIKE '".$_SESSION['Password']."'";
    $newdefectquery = "SELECT * FROM Defects WHERE Defect_Status LIKE 'New'";
    $selectallusers = "SELECT * FROM Users";

    $result = $conn->query($sql);
    $defects_new = $conn->query($newdefectquery);
    //$allusers = $conn->query($selectallusers);
?>

run query before you popup data:

<?php if ($defects_new->num_rows > 0){



while ($defect = $defects_new->fetch_assoc()){ ?>
    <table border="1" width="90%">
        <tr>
            <td colspan="2">
                <h2 style="margin:0px; font-size:25px; line-height:25px;">#<?php echo $defect['Defect_ID'] ?> - <?php echo $defect['Title'] ?> - <?php echo $defect['Found_By'] ?></h2>
            </td>
        </tr>
        <tr>
            <td width="80%">
                <?php echo $defect['Information'] ?>
                <br />
                <br />
            </td>
            <td>
                <form name="assign<?php echo  $defect['Defect_ID'] ?>" method="post" action="index.php">
                    <select name="Owner">
                    <?php $allusers = $conn->query($selectallusers); 
                          $users = $allusers->fetch_assoc();//here
                         foreach($users as $user){ ?>
                        <option value="<?php echo $user['Username']?>"><?php echo $user['Username'] ?></option>
                    <?php } ?>
                    </select>
                </form>
            </td>
            </tr>
        </table>
        <br />
        <br />
<?php } 
} else {
    echo "There are no new defects. Good job! :)";
}
 ?>

once query list all record, it will return null as there is nothing to show. You can get all user list in array in your first code part and you can loop that user array so it will execute one time.