Question

I should convert to the fallowing SQL-Query to NHibernate HQL (NHibernate 3.2). But I don’t know, how I have to translate the FLOOR, DATEDIFF and GETDATE.

SELECT Birthday FROM Person
WHERE 1 = (FLOOR(DATEDIFF(dd,Birthday,GETDATE()+10) / 365.25))
      -
      (FLOOR(DATEDIFF(dd,Birthday,GETDATE()-5) / 365.25))

Answer 1

Untested, but would something like:

var dateStart = DateTime.Now.AddDays(-5).Ticks/365.25D;
var dateEnd = DateTime.Now.AddDays(10).Ticks/365.25D;

session.QueryOver<Person>()
    .WhereRestrictionOn(x => x.Birthday.Ticks/365.25D)
         .IsBetween(dateStart).And(dateEnd)
    .List();

This do the same thing?

---

Taking a look at the source code, floor is already registered in the dialect, so the following:

var result =
    session.CreateQuery(@"from Person 
                          where 1 = (FLOOR(DATEDIFF(dd,Birthday,GETDATE()+10) / 365.25))
                                        -
                                    (FLOOR(DATEDIFF(dd,Birthday,GETDATE()-5) / 365.25))")
           .List<Person>();

Produces the following SQL:

select person0_.Id       as Id2_,
       person0_.Birthday as Birthday2_
from   [Person] person0_
where  1 = floor(DATEDIFF(dd,
                          person0_.Birthday,
                          GETDATE()
                            + 10)
                   / 365.25)
             - floor(DATEDIFF(dd,
                              person0_.Birthday,
                              GETDATE()
                                - 5)
                       / 365.25)