Can't you create an update query that pulls in information from those other tables and adds in the ancillary information you want to add to it, or does that extra information require specific details from the first query?
If you really do need to do it your way, then you'll need to do a bit of work. There's no "chuck this mixed data from different tables into another single table with extra info" function in PHP, you're going to have to create the insert query yourself.
Tell us a bit more specifically about what you're updating/adding to the retrieved data. Are you just incrementing a field, splitting a string field into different parts? Your answer could mean that a quicker way to do what you need can be found.