使用ajax Php和mysql级联下拉列表

Question

I am creating something like this and have a problem one of the dropdown. You get better understanding by the video

Video for the reference

here the source code file

here the tutorial link

Answer 1

Each time you're receving the AJAX data, you're always adding it to the next dropdown. However, you're not clearing the dropdown before you do so, and therefore you get the previous items as well.

To fix it for the Type->Model dropdowns for example (as shown in the video), you should start your populateModel() with an empty() call like this:

function populateModel(xmlindata) {

  var mySelect = $('#printermodel');;
  mySelect.empty();