CREATE TABLE table_203_674 (id DECIMAL, "name" TEXT, "mark" TEXT, "system" TEXT, "from" DECIMAL, "to" DECIMAL, "successor" TEXT, "notes" TEXT)

what now defunct railroad existed for the shortest time ?
SELECT "name" FROM table_203_674 ORDER BY "to" - "from" LIMIT 1
SELECT "name" FROM "table_203_674" ORDER BY "to" - "from" NULLS FIRST LIMIT 1