Unlike SQLTemplate, EJBQL operates in object terms, abstracted from
SQL (this is why I said earlier that it is similar to SelectQuery). So
it is free from the constraints that I mentioned and you can do
something like this:
String ejbql = "SELECT count(a) FROM Artist a WHERE " +
expression.toEJBQLString("a");
Andrus
On Jun 10, 2008, at 10:52 AM, Lachlan Deck wrote:
Hi Andrus,
On 10/06/2008, at 5:37 PM, Andrus Adamchik wrote:
On Jun 10, 2008, at 10:31 AM, Lachlan Deck wrote:
Perhaps I should describe what I'm actually doing. All I need is a
way to get a count of a select query (without having to fault in
all the related objects). So is there a way to trigger that, in
order to just get a count back, with a SelectQuery without going
the sqltemplate or namedquery route?
I think EJBQL route is the way to go for aggregate object queries.
In fact Expression has 'toEJBQLString' method, but you may not even
care about it. Anyways here is an example:
EJBQLQuery countQuery = new EJBQLQuery("SELECT count(a) FROM Artist
a WHERE a.artistName like 'A%'");
The problem is that we have a list controller that's doing its
select given the combination of various Expressions. These
expressions get broken out (at points) in order to obtain a relevant
count via some other query. So I don't have the option of
constructing the where clause as simply as above (or, in other
words, by hand).
i.e., will EJBQLQuery cope with an expression.toString() where clause?
with regards,
--
Lachlan Deck
