Non-SELECT SQL statements can be saved to and executed from the Result Manager window. See Saving SQL Code or Output and Doing More with Results for information.

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement.

As you can see, constructing a simple SELECT statement in Java is almost as simple as constructing a simple SELECT statement in SQL. The more features you want to use, the more complicated it gets.