my company bought some years ago a web-product (I don't have the source) for computing statistics and so on. The backend used is a mysql database. The structure is not complex (around 20 table) and few relationship among tables. Now our company migrated to postgree and this app is the only one using mysql. We asked the product company to privide us a new version whis postgree as backend, but for different reason they don't want to do it. So I would like to know if it exists some tools/ libraries or implementing a code layer to continue to use our app as it is, but using a postgree backend, in a certain way to cheat with the app simulating a connection to mysql and converting the mysql call (select/write/update etc.) in a postgree calls.
I just happened to run across a link to this very old blog post: Sneaking in JDBC Drivers. Heinz Kabutz knows what he's talking about but on the other hand the article is over 10 years ago and things have changed somewhat in the JDBC world since then. However the general idea is that you force your own JDBC driver to be loaded first, and then have it intercept calls from the other driver and forward those calls on to your preferred database. That could be more complicated than the example in the blog post but it may or may not be doable for what you need.