How do I append all tables from one Azure Database to another?
The easiest way to do it is going to be to SSIS to migrate the data over. The wizards alone should be able to do something this simple. The most efficient way would be to export everything to Azure blob storage and then use BULK INSERT. I'd do it all using Powershell so that you can control error handling better. It's going to be a lot more work though. If it's not that big and it's a one-time thing, I'd go with SSIS.