Database access (especially if you don't want to use servicebuilder) works exactly like in any other web application. Liferay does not mandate any specific technique/library/framework to use.
Sorry, no code snippets here (at least not from me), there are plenty of tutorials how to work with databases in web applications - on the web, in books and in trainings. The more important decision that you'll have to make is "what framework to use". So far you only told us which not to use.
