CREATE TABLE "results_pool_d" (
  "date" text,
  "score" text,
  "set_1" text,
  "set_2" text,
  "set_3" text,
  "set_4" text,
  "set_5" text,
  "total" text
);

Question: What set 2 has a set 4 of 21-25?
SQL: SELECT "set_2" FROM "results_pool_d" WHERE "set_4"='21-25';

Question: What was the score when set 3 was 26-28?
SQL: SELECT "score" FROM "results_pool_d" WHERE "set_3"='26-28';

Question: When was set 3 of 18-25?
SQL: SELECT "date" FROM "results_pool_d" WHERE "set_3"='18-25';