String queryStringText = "SELECT t.old_text FROM text t WHERE t.old_id = " + id;
Object result = session.createSQLQuery(queryStringText).uniqueResult();

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 18.02.2007 20:08:34 by Hibernate Tools 3.2.0.b9 -->
<hibernate-mapping>
    <class name="de.sonivis.tool.mediawikiconnector.generated.Text" table="text" catalog="">
        <comment></comment>
        <id name="oldId" type="int">
            <column name="old_id" />
            <generator class="assigned" />
        </id>
        <property name="oldText" type="binary">
            <column name="old_text" not-null="true">
                <comment></comment>
            </column>
        </property>
        <property name="oldFlags" type="binary">
            <column name="old_flags" not-null="true">
                <comment></comment>
            </column>
        </property>
    </class>
</hibernate-mapping>

public class Text implements java.io.Serializable {

   private int oldId;

   private byte[] oldText;

   private byte[] oldFlags;

   public Text() {
   }

   public Text(int oldId, byte[] oldText, byte[] oldFlags) {
      this.oldId = oldId;
      this.oldText = oldText;
      this.oldFlags = oldFlags;
   }

   public int getOldId() {
      return this.oldId;
   }

   public void setOldId(int oldId) {
      this.oldId = oldId;
   }

   public byte[] getOldText() {
      return this.oldText;
   }

   public void setOldText(byte[] oldText) {
      this.oldText = oldText;
   }

   public byte[] getOldFlags() {
      return this.oldFlags;
   }

   public void setOldFlags(byte[] oldFlags) {
      this.oldFlags = oldFlags;
   }

}

public class MySQL5ExtraDialect extends MySQLDialect {

   /**
    *
    */
   public MySQL5ExtraDialect() {
      super();
      registerColumnType( Types.LONGVARBINARY, 16777215, "mediumblob" );
      registerColumnType( Types.LONGVARBINARY, 65535, "blob" );
      registerColumnType( Types.LONGVARBINARY, 255, "tinyblob" );
   }
}

16.03.2007 19:35:48 org.hibernate.cfg.Environment <clinit>
INFO: Hibernate 3.2.2
16.03.2007 19:35:48 org.hibernate.cfg.Environment <clinit>
INFO: hibernate.properties not found
16.03.2007 19:35:48 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: Bytecode provider name : cglib
16.03.2007 19:35:48 org.hibernate.cfg.Environment <clinit>
INFO: using JDK 1.4 java.sql.Timestamp handling
16.03.2007 19:35:48 org.hibernate.cfg.Configuration configure
INFO: configuring from file: hibernate.cfg.xml
16.03.2007 19:35:48 org.hibernate.cfg.Configuration addResource
INFO: Reading mappings from resource : de/sonivis/tool/mediawikiconnector/generated/Text.hbm.xml
16.03.2007 19:35:48 org.hibernate.cfg.HbmBinder bindRootPersistentClassCommonValues
INFO: Mapping class: de.sonivis.tool.mediawikiconnector.generated.Text -> text
16.03.2007 19:35:49 org.hibernate.cfg.Configuration doConfigure
INFO: Configured SessionFactory: null
16.03.2007 19:35:49 org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Using Hibernate built-in connection pool (not for production use!)
16.03.2007 19:35:49 org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Hibernate connection pool size: 20
16.03.2007 19:35:49 org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: autocommit mode: false
16.03.2007 19:35:49 org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost/psiwiki
16.03.2007 19:35:49 org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: connection properties: {user=root, password=****}
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: RDBMS: MySQL, version: 5.0.21-community
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC driver: MySQL-AB JDBC Driver, version: mysql-connector-java-5.0.5 ( $Date: 2007-03-01 00:01:06 +0100 (Thu, 01 Mar 2007) $, $Revision: 6329 $ )
16.03.2007 19:35:50 org.hibernate.dialect.Dialect <init>
INFO: Using dialect: de.sonivis.tool.mediawikiconnector.MySQL5ExtraDialect
16.03.2007 19:35:50 org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory
INFO: Using default transaction strategy (direct JDBC transactions)
16.03.2007 19:35:50 org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup
INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic flush during beforeCompletion(): disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic session close at end of transaction: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch size: 15
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch updates for versioned data: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Scrollable result sets: enabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC3 getGeneratedKeys(): enabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Connection release mode: auto
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Maximum outer join fetch depth: 2
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default batch fetch size: 1
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Generate SQL with comments: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Order SQL updates by primary key: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory createQueryTranslatorFactory
INFO: Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory
16.03.2007 19:35:50 org.hibernate.hql.ast.ASTQueryTranslatorFactory <init>
INFO: Using ASTQueryTranslatorFactory
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query language substitutions: {}
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: JPA-QL strict compliance: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Second-level cache: enabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query cache: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory createCacheProvider
INFO: Cache provider: org.hibernate.cache.NoCacheProvider
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Optimize cache for minimal puts: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Structured second-level cache entries: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Statistics: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Deleted entity synthetic identifier rollback: disabled
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default entity-mode: pojo
16.03.2007 19:35:50 org.hibernate.cfg.SettingsFactory buildSettings
INFO: Named query checking : enabled
16.03.2007 19:35:50 org.hibernate.impl.SessionFactoryImpl <init>
INFO: building session factory
16.03.2007 19:35:51 org.hibernate.impl.SessionFactoryObjectFactory addInstance
INFO: Not binding factory to JNDI, no JNDI name configured

Caused by: org.hibernate.MappingException: No Dialect mapping for JDBC type: -4
   at org.hibernate.dialect.TypeNames.get(TypeNames.java:56)
   at org.hibernate.dialect.TypeNames.get(TypeNames.java:81)
   at org.hibernate.dialect.Dialect.getHibernateTypeName(Dialect.java:369)
   at org.hibernate.loader.custom.CustomLoader$Metadata.getHibernateType(CustomLoader.java:559)
   at org.hibernate.loader.custom.CustomLoader$ScalarResultColumnProcessor.performDiscovery(CustomLoader.java:485)
   at org.hibernate.loader.custom.CustomLoader.autoDiscoverTypes(CustomLoader.java:501)
   at org.hibernate.loader.Loader.getResultSet(Loader.java:1787)
   at org.hibernate.loader.Loader.doQuery(Loader.java:662)
   at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
   at org.hibernate.loader.Loader.doList(Loader.java:2211)
   at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2095)
   at org.hibernate.loader.Loader.list(Loader.java:2090)
   at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:289)
   at org.hibernate.impl.SessionImpl.listCustomQuery(SessionImpl.java:1695)
   at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:142)
   at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:152)
   at org.hibernate.impl.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:811)
   at de.sonivis.tool.mediawikiconnector.MediaWikiNetworkLoader.loadWikiLinkNetwork(MediaWikiNetworkLoader.java:345)
   ... 30 more

String queryStringText = "select t.oldText from Text t where t.oldId = ?";
byte[] result = (byte[])session.createQuery(queryStringText).setInteger(0, id).uniqueResult();
String queryText = new String(result);