what is the result for the world group, semifinals after the year 1997?
CREATE TABLE "longest_winning_streak" (
  "year" real,
  "competition" text,
  "date" text,
  "location" text,
  "score" text,
  "result" text
);
SELECT "result" FROM "longest_winning_streak" WHERE "year">1997 AND "competition"='world group, semifinals';