CREATE TABLE "first_round" (
  "team_1" text,
  "agg" text,
  "team_2" text,
  "1st_leg" text,
  "2nd_leg" text
);

Question: Which of the two teams has 1st leg of 2-0?
SQL: SELECT "team_2" FROM "first_round" WHERE "1st_leg"='2-0';

Question: Which team has an agg., that has a 1st leg of 1-2?
SQL: SELECT "agg" FROM "first_round" WHERE "1st_leg"='1-2';

Question: Which team of the team 1 column, has a 2nd leg of 1-0?
SQL: SELECT "team_1" FROM "first_round" WHERE "2nd_leg"='1-0';