How to echo previously selected option in drop down first?

Question

I am using the follow bit below. I am first querying the db to see all available options but this is for an edit form so i want the drop down to show the previously selected value so i did another query and got the selection. When i do it the way i have it below it will keep repeating the previously selected selection after each available option. HOw to fix this?

<option>Select Sales rep</option>
<?php

$query="select agent_id, agent_name from agent_names where agent_id='$ad' 
order by agent_name asc";
$result=mysql_query($query);
while(list($agent_id, $agent_name)=mysql_fetch_row($result)) {
    echo "<option value=\"".$previousname."\">".$previousselection."</option>
    <option value=\"".$agent_id."\">".$agent_name."</option>";
}


?>

Answer 1

Just check if $agent_id equals $previousname (perhaps you mean $previousid ?) and echo selected="selected" if so:

while(list($agent_id, $agent_name)=mysql_fetch_row($result)) {
    $selected = $agent_id == $previousname;
    echo "<option " . ($selected ? "selected=\"selected\"" : "") . " value=\"".$agent_id."\">".$agent_name."</option>";
}

Another option is to output the previous selected item before your while loop, and exclude it in your sql query.

Answer 2

you should take the previos selection out of the while.. like this:

<?php

$query="select agent_id, agent_name from agent_names where agent_id='$ad' 
order by agent_name asc";
$result=mysql_query($query);
echo "<option value=\"".$previousname."\">".$previousselection."</option>";
while(list($agent_id, $agent_name)=mysql_fetch_row($result)) {
    echo "<option value=\"".$agent_id."\">".$agent_name."</option>";
}


?>

and maybe even add an if so it wont repeat it self:

$query="select agent_id, agent_name from agent_names where agent_id='$ad' 
order by agent_name asc";
$result=mysql_query($query);
echo "<option value=\"".$previousname."\">".$previousselection."</option>";
while(list($agent_id, $agent_name)=mysql_fetch_row($result)) {
  if ($agent_id != $previousname) {
    echo "<option value=\"".$agent_id."\">".$agent_name."</option>";
  }
}

?>

Answer 3

You can force MySQL to return your desired result first in the list like this:

$query = "SELECT agent_id, agent_name FROM agent_names WHERE agent_id='$ad' 
ORDER BY agent_id = '{$previousname}' DESC, agent_name ASC";

This tells MySQL first to sort by agent_id matching previous selection (ie it will be 1 for the previously selected record and 0 for all others, hence sorting by it DESC makes it first in the list. And since all others will have this fields equal to 0 , they will be sorted by second field, which is agent_name ASC