I have a web application that use the generated code from an Oracle Database. Can i use the same code to connect to a MS SQL Server database if i already migrate the tables an procedures to MS SQL Server? if, yes, how i do it? if not, I need to create a new code from MS SQL Server?

You need to create a new LLBLGen project for SQLServer and generate code again. If you use Adapter templateset then the generated code consists of two projects (DBGeneric and DBSpecific). The DBGeneric project will be the same, but the DBSpecific will be specific to make the calls to SQLServer.

If you want to convert your existing project to point to SqlServer, do this: In the v3 designer you should add relational model data from the other database (like when refreshing), delete the old catalog (Oracle) and then use forward mapping (auto-map unmapped entities, by right-clicking 'Entities'). Then regenerate code.