go-sql-driver

A no-op form save got a 404 because MySQL counts changed rows, not matched rows. The fix: an existence check only on the zero path.

TL;DR: Hitting Save without changes returned 404 because MySQL reports zero affected rows when nothing actually changes. The default driver setting means zero is ambiguous and doesn't reliably indicate a missing record. The fix adds a quick existence check on zero instead of changing the global DSN setting.