I have a Parent object which has many children. Using HQL I can do a simple query to find parents which have children of a specified age like so:
"select parent from Parent as parent join Children as child where child.age=10"

I think I just learned today that if a parent has two children age 10 (twins) then I get the same parent twice. Which in SQL terms makes sense because I joined to the children collection so I end up with two result rows, one for each child. In HQL I can get the result I want by adding 'distinct' to the query.

"select distinct parent from Parent as parent join Children as child where child.age=10"

Gives me all the parents that have a child of that age, but each parent only once, just what I want. I can get the first result, the same parent repeated for each child, using the Criteria api but I can't figure out how to get the distinct list. Can I?

There is no way to specify a "distinct" Criteria at this time. I am not averse to adding this. Request it in JIRA.

Thanks Gavin, I'll do that. The Criteria API is great for the type of ad-hoc reporting that I'm doing in this app.

so the distinct feature in yet? (off of JIRA?)

my workaround lies on the java side. i.e. to make the returned collection unique through a Set.