Save two variables in input filed

I am designing a page where I let the customer to edit the name. But I can't query the name to edit . So I want the specific id to edit. But the in input filed I can set only value and I couldn't save any hidden values. How to tackle this situation. For clear understanding , In the user table user.id is the unique field and user. First name is the field I let the user to edit. so After editing I wanted to query using the id and save the updated First name. But in order to keep track of the id I couldn't find a way. Is there any way I can save multiple values in one input field.