CREATE TABLE "past_opponents" (
  "season" text,
  "competition" text,
  "round" text,
  "club" text,
  "1st_leg" text,
  "2nd_leg" text,
  "aggregate" text
);

Question: What is the club when 1st leg is 1–2?
SQL: SELECT "club" FROM "past_opponents" WHERE "1st_leg"='1–2';

Question: What is the competition when aggregate is 1–4?
SQL: SELECT "competition" FROM "past_opponents" WHERE "aggregate"='1–4';

Question: What is the 1st leg when club is a.c. libertas?
SQL: SELECT "1st_leg" FROM "past_opponents" WHERE "club"='A.C. Libertas';

Question: What is the 1st leg when 2nd leg is 1–0 and competition is uefa champions league?
SQL: SELECT "1st_leg" FROM "past_opponents" WHERE "2nd_leg"='1–0' AND "competition"='UEFA Champions League';

Question: What is the competition when 2nd leg is 0–8?
SQL: SELECT "competition" FROM "past_opponents" WHERE "2nd_leg"='0–8';

Question: What is the round when 1st leg is 0–1?
SQL: SELECT "round" FROM "past_opponents" WHERE "1st_leg"='0–1';