What team 2 had a 1st leg of 1-1, and agg of 3-1?
CREATE TABLE "first_round" (
  "team_1" text,
  "agg" text,
  "team_2" text,
  "1st_leg" text,
  "2nd_leg" text
);
SELECT "team_2" FROM "first_round" WHERE "1st_leg"='1-1' AND "agg"='3-1';