Emanuele Meazzo shows how you can use dbatools to perform a quick table-by-table data migration using Powershell:
I’m using the sqlserver and dbatools Powershell modules to accomplish such a tedious task in the fastest way possibile.
The Write-DbaDbTableData cmdlet is pretty neat because it can create automatically the destination table if it doesn’t exists, truncate the table if it exists (or append, your choice), keep the identity values and nulls if necessary and everything is done via a bulk insert with a configurable batch size.
Click through for the script. It’s not a replacement for a real ETL process but if you just need something fast, it will do the job.