A question regarding ClaimRow function. Can I use it to create a campaign where ONE SAME code will be sent to EVERYONE in my data extension, but then with my next send, the second code, which is in the second row will be sent to the entire list again? I couldn't find any documentation for my particular use case, so wondering if it's possible at all?
You can do this, use only JobID as the key field. Your ClaimRow function might look similar to this:
SET @CouponRow = ClaimRow('Coupon', 'IsClaimed', 'JobID', JobID)
This will use the same code for everyone on the same job ID. I would test this first though as batching may claim a code for each member of the first batch, and then reuse those codes.
That said, this is a very inefficient way to provide a single code to each job, as this will do a lookup for every subscriber, looking for an existing row with that JobID, then returning the same code. It would be far better to add that single code to a field in your sending DE that has the same value for every subscriber, and using the field name in the code.