Question

I’m pretty sure this particular quirk isn’t a duplicate so here goes.

I have a table of services. In this table, I have about 40 rows of the following columns:

Services:
  id_Services -- primary key
  Name -- name of the service
  Cost_a -- for variant a of service
  Cost_b -- for variant b of service
  Order -- order service is displayed in

The user can go into an admin tool and update any of this information – including deleting multiple rows, adding a row, editing info, and changing the order they are displayed in.

My question is this, since I will never know how many rows will be incoming from a submission (there could be 1 more or 100% less), I was wondering how to address this in my query.

Upon submission, every value is resubmitted. I’d hate to do it this way but the easiest way I can think of is to truncate the table and reinsert everything… but that seems a little… uhhh… bad! What is the best way to accomplish this?

RE-EDIT: For example: I start with 40 rows, update with 36. I still have to do something to the values in rows 37-40. How can I do this? Are there any mysql tricks or functions that will do this for me?

Thank you very much for your help!

Answer 1

You’re slightly limited by the use case; you’re doing insertion/update/truncation that’s presented to the user as a batch operation, but in the back-end you’ll have to do these in separate statements.

Watch out for concurrency: use transactions if you can.