trying to set option to selected where id = $id (php)

I am filling a select box with elements from a SQL database and I want to set the default value in the select box to the option that's eventID = $eventID ($eventID is a variable which we get from the previous page).

My idea was to use an if statement to check if eventID = $eventID and then set that option to selected. Like this:

    echo "<p>catDesc</p><select name='catID'>";
            while ($rowObj = $catDescQueryResult->fetchObject()) {
                if (eventID == $currentEventID) {
                    echo "<option value='{$rowObj->catID}' selected>{$rowObj->catDesc}</option>";
                }
                echo "<option value='{$rowObj->catID}'>{$rowObj->catDesc}</option>";
            }
            echo "</select>";

Here is the full PHP script:

<?php
    $eventID = filter_has_var(INPUT_GET, 'eventID') ? $_GET['eventID'] : null;


    if (empty($eventID)) {
        echo "<p>Please <a href='admin.php'>choose</a> an Event.</p>\n";
    }
    else {
        try {
            require_once("dbConnect.php");
            $dbConn = getConnection();
            // Query to retrieve event data from database
            $sqlQuery = "SELECT eventID, eventTitle,eventStartDate, eventEndDate, eventPrice, eventDescription, NE_category.catDesc, NE_venue.venueName, NE_venue.venueID, NE_events.catID
            FROM NE_events
            INNER JOIN NE_category
            ON NE_category.catID = NE_events.catID
            INNER JOIN NE_venue
            ON NE_venue.venueID = NE_events.venueID
            WHERE eventID = $eventID";
            $queryResult = $dbConn->query($sqlQuery);

            $rowObj = $queryResult->fetchObject();

            // Edit form fields are populated with existing data (all fields are editable, except the eventID) 
            echo "<h1>Update '{$rowObj->eventTitle}'</h1>
            <form id='UpdateEvent' action='updateEvent.php' method='get'>
            <p>Event ID <input type='text' name='eventID' value='$eventID' readonly /></p>
            <p>eventTitle <input type='text' name='eventTitle' size='50' value='{$rowObj->eventTitle}' /></p>
            <p>eventStartDate <input type='text' name='eventStartDate' value='{$rowObj->eventStartDate}' /></p>
            <p>eventEndDate <input type='text' name='eventEndDate' value='{$rowObj->eventEndDate}' /></p>
            <p>eventPrice <input type='text' name='eventPrice' value='{$rowObj->eventPrice}' /></p>
            <p>eventDescription <textarea name='eventDescription' rows='3' cols='100'/>{$rowObj->eventDescription}</textarea></p>
            ";


            $catDescQuery = "SELECT catDesc, catID
            FROM NE_category
            ";

            $catDescQueryResult = $dbConn->query($catDescQuery);

            echo "<p>catDesc</p><select name='catID'>";
            while ($rowObj = $catDescQueryResult->fetchObject()) {
                if (eventID == $currentEventID) {
                    echo "<option value='{$rowObj->catID}' selected>{$rowObj->catDesc}</option>";
                }
                echo "<option value='{$rowObj->catID}'>{$rowObj->catDesc}</option>";
            }
            echo "</select>";

        }
        // If the above try block is unsuccessful the user will be presented with the message below
        catch (Exception $e){
            echo "<p>Event details not found: ".$e->getMessage()."</p>\n";
        }
    }
    ?>
</select>