Hi , I have a self service generated code from LLBL gen. Here it is using a single connection string. No where I found where to change or switch the connection string. Suppose I am having more than one database in MSSQL server. I want to switch the database at run time. How to achieve this in self service generated code ? Please help me.

As stated in the documentation, you can't do that with SelfServicing, you need adapter.

http://www.llblgen.com/documentation/4.1/LLBLGen%20Pro%20RTF/hh_goto.htm#Concepts/concepts_templatesets.htm

A long time ago I also asked a question like this.....

You cannot do this at runtime, but you can do a catalog overwrite in your config file.

There is also no problem in using multiple databases when programming in SelfServicing mode. The only problem is that you cannot switch between databases at runtime. I.e. in the middle of a program.