In the previous articles, we've known about what Custom Fields is and the application of custom fields which allows users to add arbitrary information into posts. But what do you do after that? In the recent post, you also learned how to add custom fields programmatically and display them in your theme. But you’ll see a shortcoming if there is no classification and searching. This post will guide you on how to get posts by custom fields in WordPress and we'll create an interesting application: advanced search.