Windows Azure provides a variety of APIs and tools to make it easy to move data to and from cloud storage, thus simplifying deployment and migration activities.
Windows Azure SQL Database is a cloud-based relational database platform built on SQL Server technologies offering enterprise-class availability, scalability, and security. When a desktop or on-premises application is migrated to Windows Azure, any SQL Server databases used by the application are often migrated to SQL Database, so developers and IT administrators need tools for migrating data from SQL Server to Windows Azure SQL Database.
The SQL Database Import/Export Service is a tool for high-volume asynchronous transfer of data between a SQL Database in the cloud and a BACPAC file stored in Windows Azure blob storage. You can generate a BACPAC file from an on-premises SQL Server database, copy it to a container in a Windows Azure storage account (by using a tool such as the Windows Azure Management Tool (MMC) or Azure Storage Explorer), and then import that BACPAC into SQL Database through the import/export service:
The same approach can be used to export a BACPAC file from SQL Database and migrate the data to an on-premises SQL Server. For more information about the steps involved, see the MSDN article How to: Import and Export a Database (Windows Azure SQL Database). For information about how to import and export BACPAC files to an on-premises SQL Server, see Microsoft SQL Server Data Portability Documentation.
There are also many other approaches available to accomplish this type of data migration:
Windows Azure provides interoperability surfaces for all data storage options, including REST APIs for blob storage, table storage, and queue storage, as well as language-specific SDKs and APIs. A variety of tools built on top of these interoperability surfaces are available for managing Windows Azure blob storage and table storage: