If you can afford some downtime or you are performing a test migration of a production database for later migration, consider one of the following three methods:
SSMS Migration Wizard: For small to medium databases, migrating a compatible SQL Server 2005 or later database is as simple as running the Deploy Database to Microsoft Azure SQL Database Wizard in SQL Server Management Studio.
Export to BACPAC file and then Import from BACPAC file: If you have connectivity challenges (no connectivity, low bandwidth, or timeout issues) and for medium to large databases, use this manual method. With this method, you export the SQL Server schema and data to a BACPAC file and then import the BACPAC file into SQL Database using either the Deploy Database to Microsoft Azure SQL Database Wizard in SQL Server Management Studio or the SqlPackage command-prompt utility.
Use BACPAC and BCP together: Use a BACPAC file and BCP for very large databases to achieve greater parallelization for increased performance, albeit with greater complexity. With this method, migrate the schema and the data separately.
- Export the schema only to a BACPAC file.
- Import the schema only from the BACPAC file into SQL Database.
- Use BCP to extract the data into flat files and then parallel load these files into Azure SQL Database.
Source of Information : Migrating SQL Server Databases to Azure