Hello Sachin,
Unfortunately, RSVPs are tied to messages for querying as is noted here at the very top of the page: https://developer.khoros.com/khoroscommunitydevdocs/docs/rsvps
Trying to just query for a list of all the rsvp details in LiQL you get an error stating a message id is required. I tried to see if this might work as well: select * from rsvps where user.id = <ID> but I got an error indicating the message id is required.
I see how in your use case, this would be a lot of "churning" through data to get the message id to query. It could be reduced by searching over a range of time for the message ids, but I don't know if that would be an option for you or not.
To answer your question, unfortunately it doesn't seem like there is a direct way of getting what you are looking for. The information is present, but would require some churning involving multiple queries to parse through it.
Thank you,
Roger
