Hibernate version: 3.0

Hi,

I'd like to know if there's a way to access the property name of the returned results for an hql query. For example, for this query : "select client.firstName, client.lastName from Client client", i'd like to obtain metadata information that would give me access to the two property names : "firstName" and "lastName".

I found a way to access the return types ( Query.getReturnTypes() ), but not the return names.

On a JDBC ResultSet, the getResultSetMetaData() returned a structure that allowed me to get the column names. An equivalent structure could be available in an hql query via a getQueryMetadata() method.

This feature would be quite useful for the following purposes :
- Tools like the Hibernate Console could show the returned property names for an hql query.
- We could access the returned values of an hql query by name rather than by position in an Object array. For a complex select with many returned properties, this would be really useful.
- I use a generic tool to serialize the result of a query in an xml structure. I would like to use the name of the properties as the xml element names.

Thank you

I am having a very similar problem. I am trying to fit the queries into a generic JSF DataModel so that the UIData control can reference the data by column names rather than by column index. If I could get the column names I would be able to create a suitable mapping.

Apart from parsing the query string itself, I can't figure out a way to get the column names. Has anyone else tried doing this before?

I found a workaround that enabled to get me the parameter names from a named SQL query.

Session session = HibernateUtil.currentSession();
SessionFactoryImpl sessImpl = (SessionFactoryImpl) session.getSessionFactory();

NamedSQLQueryDefinition nsqlqd = sessImpl.getNamedSQLQuery( NamedQueryString );
// get the column definitons
SQLQueryScalarReturn[] columnDefinitions = nsqlqd.getScalarQueryReturns();

// get the query using the Plumtree Query Impl Helper class
Query query = PTSQLQueryImplHelper.getSQLQueryImpl(nsqlqd, (SessionImpl)session);
query.setCacheable( nsqlqd.isCacheable() );
query.setCacheRegion( nsqlqd.getCacheRegion() );
if ( nsqlqd.getTimeout()!=null ) query.setTimeout( nsqlqd.getTimeout().intValue() );
if ( nsqlqd.getFetchSize()!=null ) query.setFetchSize( nsqlqd.getFetchSize().intValue() );
List l = query.list();

The only strange part is that you need to create a helper class or a subclass that essentially creates a SQLQuery object. Since SQLQuery has a default constructor you don't have access to the class unless you are in the same package. So in the previous example my PTSQLQueryHelper class exists in org.hibernate.impl.

I am also sure you can do the same for non-named queries, although my example does not demostrate this. Cheers

Dan