Name the fleet numbers for diagram of 186 and lot number of 30798
CREATE TABLE "orders" (
  "lot_no" real,
  "diagram" real,
  "mark" text,
  "builder" text,
  "fleet_numbers" text,
  "notes" text
);
SELECT "fleet_numbers" FROM "orders" WHERE "diagram"=186 AND "lot_no"=30798;