CREATE TABLE table_203_148 (id DECIMAL, "date" TEXT, "name" TEXT, "nationality" TEXT, "tonnage\ ( grt ) " DECIMAL, "fate" TEXT)

what was the first vessel sunk in may 1940 ?
SELECT "name" FROM table_203_148 WHERE "date" = 1940 AND "date" = 5 ORDER BY "date" LIMIT 1
SELECT "name" FROM "table_203_148" WHERE "date" = 1940 AND "date" = 5 ORDER BY "date" NULLS FIRST LIMIT 1