@ryanc I downloaded SQLite 3.18, dropped into Racket’s lib folder, and verified with sqlite3_libversion_number that the new dll was being loaded. Evaluating constraint violations now returns extended error codes on Windows.

Reading the SQLite changelog, I see that extended error codes for SQL_CONSTRAINT were only added in 3.7.16 although extended code support already existed since 3.3.8. Racket’s current sqlite3.dll version is 3.7.8.