How to migrate database in ms SQL server.

Your development DB shouldn't even be on the same server instance as the production DB, much less linked in any way to the actual data.

You should be using a local-to-your-dev-machine SQL server instance (Express is fine) and a separate copy of the DB as any tiny mistake on your part - and they are easy to make when you're in a hurry to fix something - can badly affect the production data.
Or better, representative sample data in the same table structure in a local copy so you don't have to worry about data protection and GDPR.

You - the developer - shouldn't have access to production data at all!