ClassCastException (String to Long) when running a subquery with Criteria

Question

First my setups :

1. mysql-connector-java 5.1.24
2. hibernate-core 4.1.10.Final

I've got an ClassCastException when running this criteria query :

Criteria sellableItemsCriteria = session.createCriteria(MarketData.class, "md");
sellableItemsCriteria.add(Restrictions.in("region", regions));
sellableItemsCriteria.add(Restrictions.in("itemTypeId", items));
DetachedCriteria sellOrderSizeCriteria = DetachedCriteria.forClass(MarketOrder.class);
sellOrderSizeCriteria.add(Restrictions.eq("marketDataId", "md.id"));
sellOrderSizeCriteria.add(Restrictions.eq("bid", false));
sellOrderSizeCriteria.setProjection(Projections.count("marketDataId"));
sellableItemsCriteria.add(Subqueries.lt(0L, sellOrderSizeCriteria));

The exception :

Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Long

The problem is from this line (first i tried with 0 instead of 0L and i got Integer cannot be cast to Long so that why i switched to a Long) :

sellableItemsCriteria.add(Subqueries.lt(0L, sellOrderSizeCriteria));

And this is the mysql query i want to run :

SELECT md.* FROM `marketdata` md
WHERE md.region IN (:regions) 
AND md.item_typeID IN (:items) 
AND (SELECT COUNT(marketData_id) FROM `marketorder` WHERE marketData_id = md.id AND bid = 0) > 0

How can i resolve the cast problem ?

Or maybe there is a better way to do this with Criteria ?

Thanks

Answer 1

I'm pretty sure you'll find that the exception comes in fact from this line:

sellOrderSizeCriteria.add(Restrictions.eq("marketDataId", "md.id"));

This line tries to compare the marketDataId property of MarketOrder to the String "md.id". That's not what you want to do. What you want to do is to compare the marketDataId property of MarketOrder to the id property of md. And you thus need to use eqProperty() instead:

sellOrderSizeCriteria.add(Restrictions.eqProperty("marketDataId", "md.id"));