Question

Is it possible to do indexed element access in JPQL like in HQL :

select o from Order o where o.items[0].id = 1234

I couldn’t find something related in the JPA 2 specs,

I am targeting EclipseLink JPA here, so if you come up with an EclipseLink solution, that’s ok as well, although a JPQL standard solution is preferred.

Answer 1

The INDEX function should do the trick (actually I tested it and it does):

SELECT o
FROM Order o JOIN o.items i
WHERE i.id = 1234
AND INDEX(i) = 0

From the JPA 2.0 specification (4.6.17.2.2 Arithmetic Functions):

The INDEX function returns an integer
value corresponding to the position of
its argument in an ordered list. The
INDEX function can only be applied to
identification variables denoting
types for which an order column has
been specified.