iron-data-table | Web Component for displaying data | Grid library

I have some issues with dynamic tables component from Polymer. Here is what I would like to achieve: I would like to send a sql request with an ajax request and update the table with the response of that request.

So far what I have managed to do is that I send my sql request, the server then creates a .json file with the data, then I use another request to get that file and put it into the table.

Problem is that I have to refresh the entire web page in order to get the table filled.

Is there any way to update the table directly with the response of the first ajax request, and not using a json file ?

Here is my code:

I'm using iron-data-table loaded with JSON data from iron-ajax. I let the user select multiple lines and click "delete". The list is sent to the backend and is deleted from the database.