Rapid SQL is described as 'Create high-performing SQL code on major DBMSs from one interface' and is an app in the Development category. There are three alternatives to Rapid SQL for Windows, Wine and Linux. The best alternative is dbForge Studio for Oracle, which is free. Other great apps like Rapid SQL are FlySpeed SQL Query (Freemium) and Dbartisan (Paid).
dbForge Studio for Oracle is a powerful integrated development environment (IDE) which helps Oracle developers to increase PL/SQL coding speed, provides versatile data editing tools for managing in-database and external data.
If you are looking for a proper tool to work with data and SQL queries with ad-hoc visual query builder, you must have a look at FlySpeed SQL Query. It connects to all modern database servers and works with all popular desktop databases and office file formats (CSV, Excel).