填充的mysql中的未定义索引选择设置时选择

Question

I have a select dropdown that is being populated and displayed correctly from a mysql query:

  <select name="title">
  <option></option>
  <?php
    while($row = mysql_fetch_assoc($title_data)) {
      echo '<option value=' . $row["title"];
      echo '>' . $row["title"];
      echo '</option>';
    } 
  ?>
  </select>

When I add code to check which row was selected, I get an undefined index error for each row in the query results:

  <select name="title">
  <option></option>
  <?php
    while($row = mysql_fetch_assoc($title_data)) {
      echo '<option value=' . $row["title"];
      if($_POST["title"] == $row["title"]) {
        echo ' selected';
      }
      echo '>' . $row["title"];
      echo '</option>';
    } 
  ?>
  </select>

I'm realtively new to this and may be missing something obvious. I had checked the posts and did not see this particular example where I am using a while loop from a query and trying to echo the selected attribute. The actual error text is inserted into the dropdown box:

Notice: Undefined index: title in C:\xampp\htdocs\indexdb.php on line 215 >Analyst I" and appears for each row in the dropdown box.

I apologize if this has been covered as I stated, this is my first php code and is a protype only. This is the only hurdle I have not been able to overcome.

Answer 1

You need to encapsulate the value attribute's data.

echo '<option value="' . $row["title"] . '" ';

Then to resolve the undefined index first check that the field is populated:

if(!empty($_POST["title"]) && $_POST["title"] == $row["title"]) {