Hello!
I am writing an application that uses Hibernate.
And I need a specific HQL query:

select count(distinct date(o.date)) from MyObject o;

As you see, I want to select all unique dates.
The problem is that date property of the class MyObject represents date and time,so if I use following select count(distinct o.date) from MyObject o; I do not get what I really need.
So hibernate doesn't like that date function, that converts from dateTime to date.
Any ideas? Help please!

fevzi,

The Date type in Oracle and others does store date and time, despite its name. If the time is not indicated, 12:00 midnight is used.
Therefore, a SELECT DISTINCT by that field alone, if you never specify time, should return different dates only.

If your time is also specified, but you want to achieve a distinct by date only, you can use Hibernate HQL's supported functions day() , month() and year(), and peform a SELECT DISTINCT by those.