Abusing SQL to Play DOOM

Most laypeople who encounter SQL think of it purely as a tool for managing large datasets. While that is certainly what it was designed for, SQL is still a programming …. It includes many of the features found in general-purpose languages like C or Python, and although it wasn’t built for general-purpose work, it can handle a surprising range of tasks that programmers might not expect to use it for.

To demonstrate its capabilities, and perhaps to show off their skills with SQL, a group at CedarDB ported the original DOOM to this language. The project stores the WAD data (essentially everything except the engine) in a series of tables, which was fairly straightforward compared to the rest of the project. Where it gets more complicated is managing the timing that ties the game to 35 fps, and of course rendering the images.

Their rendering process takes up 1300 lines of SQL across 89 common table expressions (CTEs) which is certainly advanced for this language. The rest of the project is another 4000 lines of SQL, with a bit of Python to handle the keyboard inputs, timing, and display of the generated bitmap.