I have a column in MySQL which is a smallint unsigned. I am using a short type for this in the hbm.xml file but Hibernate is not liking this in a where clause. What is wrong with this type and how can I track it down?

Thanks,
SZ


net.sf.hibernate.QueryException: could not resolve property type: forumid [select thread.threadid, thread.forumid, thread.title, thread.postusername, thread.replycount, thread.dateline from ForumThread as thread where thread.forumid = 5 order by thread.threadid desc]
at net.sf.hibernate.hql.PathExpressionParser.getPropertyType(PathExpressionParser.java:235)
at net.sf.hibernate.hql.PathExpressionParser.end(PathExpressionParser.java:281)
at net.sf.hibernate.hql.WhereParser.doPathExpression(WhereParser.java:366)
at net.sf.hibernate.hql.WhereParser.doToken(WhereParser.java:393)
at net.sf.hibernate.hql.WhereParser.token(WhereParser.java:279)
at net.sf.hibernate.hql.ClauseParser.token(ClauseParser.java:87)
at net.sf.hibernate.hql.PreprocessingParser.token(PreprocessingParser.java:120)
at net.sf.hibernate.hql.ParserHelper.parse(ParserHelper.java:29)
at net.sf.hibernate.hql.QueryTranslator.compile(QueryTranslator.java:146)
at net.sf.hibernate.hql.QueryTranslator.compile(QueryTranslator.java:133)
at net.sf.hibernate.impl.SessionFactoryImpl.getQuery(SessionFactoryImpl.java:352)
at net.sf.hibernate.impl.SessionFactoryImpl.getQuery(SessionFactoryImpl.java:330)
at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1368)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1332)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1322)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1314)
at PassedThreads.query(PassedThreads.java:28)
at PassedThreads.main(PassedThreads.java:40)

Is it really forumid, or actually forumId? Show your mapping,

Mapping revealed:

<hibernate-mapping>
<class name="ForumThread" table="thread">
<id name="threadID" type="integer" column="threadid">
<generator class="native"/>
</id>
<property name="title" column="title"/>
<property name="postUserName" column="postusername"/>
<property name="replyCount" column="replycount" type="integer"/>
<property name="dateLine" column="dateline" type="integer"/>
<property name="forumID" column="forumid" type="short"/>
</class>
</hibernate-mapping>

As Gavin was pointing out your property references have Case so you need to use case, eg,

select thread.threadID, thread.forumID, thread.title, thread.postUserName, thread.replyCount, thread.dateLine from ForumThread as thread where thread.forumID = 5 order by thread.threadID desc

Fastest open-source responses I've seen. Thanks.

Since I am using the hibernate2 reference documentation, my contribution back would be to suggest that a paragraph be added in the quickstart section which explains that the query parameters are the class' attribute names and not the table column names. It is easy to miss this with the cat example because there is no difference between the column names and the class attribute names. For somebody racing to get an example up it is easy to miss because the standard SQL paradigm is to use column names. This difference is fundamental and would justify a mention up front.

Still have one more problem, though.

I am getting a class cast exception on the following code:

try {
session = HibernateUtil.currentSession();
Transaction tx = session.beginTransaction();
List threads = session.find(sql);
System.out.println(threads.size() + " thread(s) found");

for (Iterator it = threads.iterator(); it.hasNext();) {
ForumThread thread = (ForumThread) it.next();
System.out.println(thread.getTitle());
}
tx.commit();
} catch (HibernateException e) {
e.printStackTrace();
}

However, this only happens with the full hb-sql (see above) and in spite of the fact that it returns the right number of rows.

If I do something real simple like:

String sql = "from ForumThread";

it works just fine.

Can you clear up this mystery??
Thanks.

Since mapping problems seem like a big stumbling block, it would be nice if there was a debugging level that would print a list of the fields mapped for a persistent class when there is a mapping error. That way a user could immediately see what the fields are and compare with the erroneous query field.

We use this type of debugging for printing event dispatch tables when an event comes in to a dispatcher that doesn't match any of the registered events. It saves a lot of time tracking down errors.

Just an idea.

OK, got it. I put the where clause after the 'from ForumThread as thread' clause.

Sorry, it takes a few mistakes to grok that you are really dealing with an OO query language which just resembles SQL.

Here again, it would be great to see some introductory material highlighting the paradigm shift between using SQL and HBSQL.

Good suggestion, I'll add it to the documentation.