Table: confed_cup_2008
Columns: team_1
agg
team_2
1st_leg
2nd_leg

Question: What is the 1st leg that has a 2nd leg of 0–0 of olympique khouribga?
SQL: SELECT "1st_leg" FROM confed_cup_2008 WHERE "2nd_leg" = '0–0' AND "team_1" = 'olympique khouribga'

Question: What is the 1st leg of cs sfaxien?
SQL: SELECT "1st_leg" FROM confed_cup_2008 WHERE "team_2" = 'cs sfaxien'