Migrate your Legacy Oracle Database application to Java with JDBCWizard

JDBCWizard can save hundreds of hours of work when rewriting legacy applications in Java


You need to migrate from Delphi (or Visual Basic) to Java but the legacy oracle database has a lot of logic written in PL/SQL and living in the Oracle database backend.

Devising a legacy code migration strategy for Delphi + Oracle + PL/SQL

Even though the system has a lot of complex PL/SQL rewriting it as part of a legacy migration stratecy doesn't really make any sense. The PL/SQL back end of the system presumably works and there is no reason it has to change. But many developers on looking at this situation will be instinctively pulled in the direction of rewriting everything, even though it represents a massive and totally unwarranted increase in scope. Why total rewrites are usually a bad thing is very well covered by Joel Spolsky in his well known ' things you should never do' blog posting.

One of the main arguments you can expect to hear in favour of a rewrite is that even if the PL/SQL remains the same there is no way to convert the legacy Delphi ODBC calls to Java's JDBC calls, and that as a result a large amount of time and energy must be devoted to writing JDBC calls by hand, and that if we 'got rid' of the PL/SQL we could reduce the amount of code to be written. This is flawed for two reasons.

Firstly, PL/SQL procedures often bundle many seperate SQL statements into one call, which implies an increase in the number of JDBC invocations that need to be written.

Secondly, there are significant performance advantages to be obtained by clumping SQL statements into strored procedures.

So given that rewriting our legacy PL/SQL as part of a plan to change Delphi to Java doesn't make much sense how are we going to create the Java needed to call our legacy PL/SQL? This is where JDBCWizard comes in...

A real world example in which 6 man months of development time was saved

We encountered a customer who needed to upgrade a legacy solution and had several hundred PL/SQL procedures that were part of a legacy digital content management application. Because they were changing languages not a single line of the legacy client code was reusable. But there was absolutely nothing wrong with the Oracle PL/SQL layer, except that all the calls to access it were written in Delphi. Manually writing the JDBC calls was possible, but even assuming it would take an average of 2 hours per procedure by the time testing was done this was still more than 6 months of development time without any value being created for the customer.

By using JDBCWizard our customer was able to cut this down to a couple of weeks. As part of the purchase we provided email technical support and know-how, and by the end of the project the customer was self sufficient and no longer needed our assistance.

Information on downloading a demo version of JDBCWizard is available here , and ordering information is here .