selected value get from db into dropdown select box option using php mysql error

Question

I need to get selected value from db into select box. please, tell me how to do it. Here is the code. Note: 'options' value depends on the category.

<?php 
  $sql = "select * from mine where username = '$user' ";
  $res = mysql_query($sql);
  while($list = mysql_fetch_assoc($res)){
    $category = $list['category'];
    $username = $list['username'];
    $options = $list['options'];
?>

<input type="text" name="category" value="<?php echo '$category' ?>" readonly="readonly" />
<select name="course">
   <option value="0">Please Select Option</option>
   <option value="PHP">PHP</option>
   <option value="ASP">ASP</option>
</select>

<?php 
  }
?>

Answer 1

I think you are looking for below code changes:

<select name="course">
<option value="0">Please Select Option</option>
<option value="PHP" <?php if($options=="PHP") echo 'selected="selected"'; ?> >PHP</option>
<option value="ASP" <?php if($options=="ASP") echo 'selected="selected"'; ?> >ASP</option>
</select>

Answer 2

The easiest way I can think of is the following:

<?php

$selection = array('PHP', 'ASP');
echo '<select>
      <option value="0">Please Select Option</option>';

foreach ($selection as $selection) {
    $selected = ($options == $selection) ? "selected" : "";
    echo '<option '.$selected.' value="'.$selection.'">'.$selection.'</option>';
}

echo '</select>';

The code basically places all of your options in an array which are called upon in the foreach loop. The loop checks to see if your $options variable matches the current selection it's on, if it's a match then $selected will = selected, if not then it is set as blank. Finally the option tag is returned containing the selection from the array and if that particular selection is equal to your $options variable, it's set as the selected option.