return sql query results to to the page that its executed from?

I am developing a website where I need to search the customers table, and the user needs to specify the Customer_No that they wish to search for. I know how to perform the query using an onsubmit, but this seems a bit clunky to me and I would like it if there was a way to perform the query and return the results to the same page that the information was entered on.

I'm basically looking for a way to run a php script from an onclick, like how you would with javascript. Sorry if this is worded quite badly, I'm not the most experienced when it comes to web development. Any help or guidance on how i could solve this would be great.