Overlapping records between two dates using Linq

Question

In my application a user can delegate another user to approve orders.

What I need to validate, is that there are no circular references so if User A is

Answer 1

Can't you simply do

var doesOverlapExist = Session.QueryOver<DelegateOrderApproval>()
     .Any(x => 
        x.DateFrom > DateTime.Now && 
        delegateOrderApproval.DelegatedUser.UserId == x.DelegatorUser.UserId &&
        x.DateFrom <= delegateOrderApproval.DateTo &&
        x.DateTo >= delegateOrderApproval.DateFrom);

or if you don't have any, replace with

Where(x=> blabla).Count() >0

overlap check logic : Determine Whether Two Date Ranges Overlap