I have Created connection to BI System. It contains 10 years data with monthly basis. now, I need to get last 36 months data from that in crystal report . how to acheive this.
The solution depends on what database your using - kinda as there are some good database functions you could use.
However, regardless of the database, you could probably achieve this using the dateadd() functions and subtracting 36 months from one of the date fields you have then then using this in a selection formula. You might need some extra stuff if you need to do it from the first day of the month in the starting month.