Hello everyone,

I have three classes: Department, County, and Zipcode. Each Department is mapped to a set of counties that are associated with it, and each County has a set of mapped Zipcodes.

I am having difficulty getting a Department by Zipcode. The following HQL gives an error:

from Department as h where h.counties.id = (select c.id from County as c where c.zipcodes.id = (select z.ip from Zipcode as z where z.zipcode = '"+zipcode+"'))"

I've also tried:

from Department as h where h.counties.zipcodes.zipcode=zipcode

with same result. The error I get is:

"illegal attempt to dereference collection".

Ultimately, I've realized that where i am having trouble is manipulating the collections/set i get returned using h.counties or c.zipcodes.

Any help will be appreciated.

Implicit join doesn't work with collections. You need to do an explicitly join. For example, something like this:

Thanks. That made some progress. However, I now get a java.lang.ClassCastException thrown when i do:
department = l.get(0);

The idea is to get a department object. Sounds like the query is not returning just a department object.

Oh.. I'm sorry. I tend to forget that when you use explicit joins the query returns all joined entities as well in an Object[]. If you only need the Department you need to specify what to select:



In the original form you would get an Object[] of length 3 with:

department = a[0], county = a[1] and zipcode = a[2]