Adventures of a Software Engineer

Tag: hibernate

  • No Dialect mapping for JDBC type: -4

    Yet another fun day with hibernate.
    While working on ResourcePhaseListener for JSF attachment problem I run into following problem while trying to retrieve BLOB from MySQL db.

    org.hibernate.MappingException: No Dialect mapping for JDBC type: -4 No Dialect mapping for JDBC type: -4

    Here is the offending code:

    SerializableBlob result= null;
Session hibSession=(Session) em.getDelegate();
result = (SerializableBlob)	
hibSession.createSQLQuery("Select DATA from Table")	
.addScalar("DATA", Hibernate.BLOB)			
.uniqueResult();

    Adding the mapping addScalar("DATA", Hibernate.BLOB) solved the problem.

  • Show last executed query SQL Server – Disected

    I found this online, without explanation so I will dissect the query and explain what is happening.

    SELECT deqs.last_execution_time AS [Time], dest.TEXT AS [Query]
FROM sys.dm_exec_query_stats AS deqs
CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest
ORDER BY deqs.last_execution_time DESC

    This beautifully crafter query will show us last few queries executed on they db, very usefull for seeing what is Hibernate generating for us.