Hi

I have some very old code in a project. Its a java webapp using tomcat as the server.

The project use a single bean that handles sql queries and sql updates. The bean has two methods get and set and they take an SQL string and use JDBC via tomcat connection pool to either perform the query and turn it into a vector of vector of string or initiate an update and return last insert ID . Of course this needs to change.

The problem I have is the project is very large and I cant migrate everything - including all queries etc to hibernate in one go, but some of the new functionality would of course benefit from a better approach while we slowly remove or the old ways.

So question is can I continue to have the old SQL beans doing what it does and also use hibernate. They would both share the tomcat connection pool.

Will doing transactional hibernate stuff be interfered with by performing queries elsewhere using the old bean. I dont mean at the actual database transaction level but more in terms of will hibernate have issue with other queries going on it does not know about ?

It should be fine because transactions are coordinated at JDBC level. It's best if you make the transition at service level and avoid calling DAO belonging to different approaches.