Hibernate SQLQuery

In the last week I have seen this error twice when running native SQL queries to a MySQL database using Hibernate. (I am forced to use SQL - not my first choice.)

No Dialect mapping for JDBC type: -1

It took me a while to find the answer, so I thought I would share.

The problem this time is that the data I was retrieving was a longtext column (not a regular varchar) and this is not automatically mapped by the MySQL dialect (I believe this is fixed in Hibernate 3.5).

I solved the problem by using "addScalar" to define the mapping to use. It worked!

 Query query = getSession()
   .createSQLQuery("select data from form_data where form_data_id = ?")
   .addScalar("data", Hibernate.TEXT)
   .setInteger(0, formData.getId());
  String oldData = ((String)query.uniqueResult());