如何在动态下拉列表中设置默认值

Question

I have a drop down select populated dynamically from a MySQL database and I need to default the drop down value to display based on which record the user selected. What I have so far is not displaying any values in the drop down. But I have code that is outside of the select option statement and it displays the defaulted value in bold. I just can't seem to get the drop down to walk through the if statement logic.

A user selects a record from the data table and clicks edit. For example the user selected a row that is highlighted in grey then clicks edit that sends them to an edit form

Edit form: I pass the unit id to the edit form and pre-populate the input fields based on the passed id but here is where I can't populate and set the default drop down option values

Here is the code behind the edit form for the drop down select (div id drop down)

    define('DBHOST','localhost');
    define('DBUSER','root');
    define('DBPASS','*********');
    define('DBNAME','fdmamaint');

    if (!$db = new mysqli(DBHOST, DBUSER, DBPASS, DBNAME)) die("Can't connect to database");

 // Retrieve the record the user selected
    $id = htmlspecialchars($_GET["id"]); 

// Query the depunits table based on the user selection 
    $sql = "SELECT unit_id, div_id, title_org, short_desc, long_desc, unit_desc, avail_ind "
            . "FROM depunits "
            . "WHERE unit_id=$id";
    if (!$result = $db->query($sql)){
            die("There was an error running the query [" .$db->error. "]");
    }

// Walk through the result set and assign variables for reference later on in the script
    while ($row = $result->fetch_assoc()){
        $unitId = $row['unit_id'];
        $divId = $row['div_id'];
        $titleOrg = $row['title_org'];
        $shortDesc = $row['short_desc'];
        $unitDesc = $row['unit_desc'];
        $longDesc = $row['long_desc'];
        $enabled = $row['avail_ind'];
    }

  // Div Id - query database to get drop down select options
    $divSelect = "SELECT div_id, long_desc FROM depdivisions "
            . " WHERE div_id <> '' and avail_ind='Y' and active_ind='Y'"
            . " ORDER BY div_id";
    if (!$divResult = $db->query($divSelect)){
            die("There was an error running the query [" .$db->error. "]");
    }

.......

Dynamic drop down select:

<!-- Div Id -->                                        
<label for="divId" class="control-label">Div Id</label>
   <select class="form-control" name="divId" id="divId">
       <option value=" "></option>
       <?php
          while ($rowDivs = $divResult->fetch_assoc()) 
         {
            $data = '37' .$rowDivs['div_id'];

            // if the value of $data matches the value of div id of the 
            // user selected row in the database then give that option 
            // value the selected tag                                      
            if ( $data == $divId) 
            {
               echo "<option value=". $data ."selected>";
               echo $data ;
               echo "</option>";
            }
            else 
            {
               echo "<option value=". $data .">";
               echo $data;
               echo "</option>";
            }
          }

Can I have an if/else statement within the php while statement? Is that maybe why I'm not getting any data results in the drop down?

Answer 1

I figured it out:

I needed to use an inline if statement like so:

<!-- Div Id -->                                        
<label for="divId" class="control-label">Div Id</label>
   <select class="form-control" name="divId" id="divId">
       <option value=" "></option>
       <?php
          while ($rowDivs = $divResult->fetch_assoc()) {

              $data = '37' .$rowDivs['div_id'];
              echo "<option value=$data" .($data == $divId ? ' selected="selected"' : '') . ">$data</option>";  
          }     
       ?>
   </select>