Hibernate: 3.1rc1
Hibernate annotations: 3.1beta6
Database: PostgreSQL 8.1beta3

I'm using a fetch join for a one-to-many relationship with lazy loading, e.g. one customer has several orders. When I submit a named query to retrieve customers and load their orders orders, too, then each customer object will be duplicated. For instance, if customer with id=1 has 3 orders then I'll get 3 customer objects each having id=1.

The named query is defined as follows:
SELECT DISTINCT c
FROM CustomerData c LEFT JOIN FETCH c.orders
WHERE c.name = :name

I understand the semantics of a left outer join. However, I'd expect that the "SELECT DISTINCT" option would eliminate duplicates from the result set.

Any hint is appreciated!

when you say DISTINCT c, the records which are returned will be distinct with respect to all the collumns on the table Customerdata, it wont be on a single collumn.

you should specify the collumn name else all the collumns will be considered.

Abhi
Rate it if solves your problem

Specifying a column name returns duplicate values, too. I'll submit a bug report.

Don't,
To distinct you objects when fetch is used, use a HashSet

so, if i want to keep the right order of list, i should use LinkedHashSet insteed, am i right?

i have the same duplicate problem, is it a bug or a feature?

Having the duplicates is a feature (see FAQ). Using LinkedHashSet is a reasonable solution to preserve the ordering.