I was asked to map a few of the old reports to a different datasourse. (new server). When I check the reports, all of them were based on ADD COMMAND (sql statements) not tables, stored procedures or views. Those were complicated reports having grouping, formulas, conditional suppression in it, it would a big task to re-write the reports again from scratch. I use to standard method of setting the datasourse location to the new datasource. This method works fine for Views, Stored procedures, tables not for (add command) command objects. I tried many different methods but never succeeded. I ask on this website for help too, but no one replied to my Thread. I kept on trying different things and now finally I have solved the problem. You need to close all existing instances of Crystal reports (if there are any open). Open the report in a new instance of crystal reports. Then In the database menu, go to verified database. You will see a screen having existing Service, User ID, and password. Put the name of the new datasourse (new server) in the service text box, enter the user ID, and password and the command object will automatically be mapped to the new datasourse in a very quick way.
NOTE:- (if the report got verified directly without prompting for the username and password, means you are using an existing instance of crystal and you have to close the connection with the database of the existing instance before verifying the database)