Table: uefa_champions_league_matches_2
Columns: team_1
agg
team_2
1st_leg
2nd_leg

Question: What is team 1 when team 2 is Manchester United?
SQL: SELECT "team_1" FROM uefa_champions_league_matches_2 WHERE "team_2" = 'manchester united'

Question: What is the agg when team 1 is Milan?
SQL: SELECT "agg" FROM uefa_champions_league_matches_2 WHERE "team_1" = 'milan'