develop one application in windows azure with back end as sql server

i'm new in windows azure.. I want to develop one application in windows azure with back end as sql server so for that code pattern same as .net 3 tire architecture or different code pattern follow for windows azure??

in .net we use EAL,DAL, BAL class libraries and take reference in our web site same structure follow for this windows azure application or other like(three worker role create for 开发者_StackOverflow社区our EAL,DAL,BAL libraries )??

Thanks in advance

Windows Azure doesn't force you into any particular architecture such as 3-tier - that's up to you to decide.

If you want to connect to SQL Server, you'll need:

• A connection string to your SQL Server database
• An on-premise SQL Server installation
• Either a hole in your firewall or a Windows Azure Connect VPN connection

Accessing a SQL Server outside the data center will incur bandwidth costs.

You could install SQL Server in a VM Role, but this is currently unsupported, and you wouldn't be able to do much for performance (your data would need to be stored in a Cloud Drive, which is in a Page Blob) or scaling (only one VM instance can write to a Cloud Drive). I wouldn't recmommend going down that path.

You could also consider migrating your database to SQL Azure, which is a substantial subset of SQL Server. Then you'd avoid bandwidth costs and not have to worry about supporting a database server (SQL Azure is Database-as-a-Service, with a connection string that looks just like a SQL Server connection string). There's a SQL Azure Migration Wizard that analyzes your database schema and attempts to convert it to SQL Azure.

For more information about SQL Azure, look here. Lots of good stuff, including detailed differences between SQL Server and SQL Azure.

For information about Windows Azure Connect, look here.