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

Question: What is Set 4, when Set 1 is 19-25, and when Set 2 is 23-25?
SQL: SELECT "set_4" FROM "results_pool_b" WHERE "set_1"='19-25' AND "set_2"='23-25';

Question: What is Set 1, when Set 4 is NA, when Score is 3-0, and when Set 2 is 29-27?
SQL: SELECT "set_1" FROM "results_pool_b" WHERE "set_4"='na' AND "score"='3-0' AND "set_2"='29-27';

Question: What is Set 2, when Date is May 31?
SQL: SELECT "set_2" FROM "results_pool_b" WHERE "date"='may 31';

Question: What is Set 1, when Set 2 is 17-25?
SQL: SELECT "set_1" FROM "results_pool_b" WHERE "set_2"='17-25';

Question: What is Set 3, when Set 4 is 25-21, and when Date is Jun 14?
SQL: SELECT "set_3" FROM "results_pool_b" WHERE "set_4"='25-21' AND "date"='jun 14';