避免使用php重新加载页面或重置选择下拉列表

Question

I'm new to PHP programming and working with backend. I know what I am doing, but having trouble finding a proper solution online which matches my case.
Basically, I have a form (2 text fields, 3 dropdowns) that filters the data that I am getting from SQL Server (that works). However, when I press the "filter" button and I get the desired results, the page reloads and resets the form. Now I have the filtered records but I don't know what filters I used to get that.
I could insert a <?php ... ?> if else, but the thing is I already am using php to get the dropdown values. Don't think I can put php inside php. By including if-else I mean this:
echo '<option value="' . $row['status'] . '"' . if($prod_status == $row['status']): echo ' selected="selected"' . '>' . $row['status'] . '</option>';
Here's the code:

<label for="prod_status_filter">Prod Status</label>
<select class="form-control" id="prod_status_filter" name="prod_status_filter">
<?php
    $query_status = 'select DISTINCT status FROM analytics.laborrecords ORDER BY status ASC';
    $result = sqlsrv_query($conn, $query_status);
    while ($row = sqlsrv_fetch_array($result, SQLSRV_FETCH_ASSOC))
    {
        echo '<option value="' . $row['status'] . '">' . $row['status'] . '</option>';
    }
?>
</select>

This is one of the dropdowns.

I want:
1. Either stop the page from reloading so the filter dropdowns remain the same. (AJAX won't work, I have 3 dropdowns with a lot of options and it's doesn't seem like a good practice to make so many getElementById lines)
2. Let the page reload but keep the values as I set until I want to reset them, with a "reset" button.

Answer 1

You have to populate the form using the submitted form data. It should be either in $_POST or $_GET .

Check if the value of $_POST['prod_status_filter'] matches the value in $row['status'] and if it does, echo selected.

Be sure to sanitize the form data. Never trust user input.