.class parameter in HQL query not converted into discriminator value properly ----------------------------------------------------------------------------- Key: HHH-1836 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1836 Project: Hibernate3 Issue Type: Bug Components: query-hql Affects Versions: 3.0.5 Environment: Win XP SP2, Hibernate 3.0.5, Sun Java 1.5.0_06 Reporter: Ignat Zapolsky Hello! I have following problem: when using HQL query "select item.id, item.name from Item as item where item.class = ?" and trying to use clause Query.setParameter (0, SubItem.class) I am getting following exception from underlying database since hibernate doese not properly convert parameter into associated discriminator value: 2006-06-14 15:04:30,828 WARN [org.hibernate.util.JDBCExceptionReporter] - <SQL Error: -16, SQLState: 37000> 2006-06-14 15:04:30,828 WARN [org.hibernate.util.JDBCExceptionReporter] - <SQL Error: -16, SQLState: 37000> 2006-06-14 15:04:30,843 ERROR [org.hibernate.util.JDBCExceptionReporter] - <Wrong data type: For input string: "Item"> 2006-06-14 15:04:30,843 ERROR [org.hibernate.util.JDBCExceptionReporter] - <Wrong data type: For input string: "Item"> org.springframework.jdbc.UncategorizedSQLException: Hibernate operation: could not execute query; uncategorized SQLException for SQL [select abstractco0_.id as col_0_0_, abstractco0_.name as col_1_0_ from TABLE abstractco0_ where abstractco0_.type=?]; SQL state [37000]; error code [-16]; Wrong data type: For input string: "Item"; nested exception is java.sql.SQLException: Wrong data type: For input string: "Item java.sql.SQLException: Wrong data type: For input string: "Item" at org.hsqldb.jdbc.Util.throwError(Unknown Source) at org.hsqldb.jdbc.jdbcPreparedStatement.setParameter(Unknown Source) at org.hsqldb.jdbc.jdbcPreparedStatement.setString(Unknown Source) at org.hibernate.type.StringType.set(StringType.java:24) at org.hibernate.type.ClassType.set(ClassType.java:35) at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:62) at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:44) at org.hibernate.loader.Loader.bindPositionalParameters(Loader.java:1115) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1177) at org.hibernate.loader.Loader.doQuery(Loader.java:390) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:218) at org.hibernate.loader.Loader.doList(Loader.java:1593) at org.hibernate.loader.Loader.list(Loader.java:1577) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:395) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:271) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:844) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:74) Please also examine bug http://opensource.atlassian.com/projects/hibernate/browse/HHH-1749 it observes situation from discriminatort to class point of view. PS. There are several forum posts regarding almost same issues: http://forum.hibernate.org/viewtopic.php?t=956408&highlight=discrimin... http://forum.hibernate.org/viewtopic.php?t=941125&highlight=discrimin... PPS. If required I could provide sample mappings and code snippets.