Question

As part of my Java program, I need to do a run a lot of queries against (Oracle) database.

Currently, we create a mix SQL and Java, which (i know) is a bad bad thing.

What is a right way to handle something like this? If possible, include examples.

Thank you.

EDIT:

A bit more information about the application. It is a web application that derives content mainly from the database (it takes user input and paints content to be seen next based on what database believes to be true).

The biggest concern I have with how it’s done today is that mixing Java code and a SQL queries look “out-of-place” when coupled as tightly as it is (Queries hardcoded as part of source code)

I am looking for a cleaner way to handle this situation, which would improve maintainability and clarity of the project at hand

Answer 1

For what you’ve described, incorporating an object relational mapper (ORM) or rewriting as stored procedures is probably more work than you want to embrace. Both have non-trivial learning curves.

Instead a good practice is consolidating SQL in a class per table or purpose. Take a look at the table data gateway object and the data access object design patterns to see how this is done in practice.

The upshot of this approach is myriad. You are better positioned for reuse because queries are in one spot. Client code becomes more readable as you replace several lines of JDBC and SQL with a method call (e.g. userTableDataGateway.getContentToShow(pageId)). Finally, this will help you see the problem more clearly an ORM helps solve.