Table: grasshopper_zurich_matches
Columns: season
competition
round
opponent
series

Question: What is the Season when the Opponent was zenit st. petersburg?
SQL: SELECT "season" FROM grasshopper_zurich_matches WHERE "opponent" = 'zenit st. petersburg'

Question: What is the Opponent with a Round of q2, in the 2005–06 season?
SQL: SELECT "opponent" FROM grasshopper_zurich_matches WHERE "round" = 'q2' AND "season" = '2005–06'

Question: What is the Competition for Season 2002–03, and the Opponent was zenit st. petersburg?
SQL: SELECT "competition" FROM grasshopper_zurich_matches WHERE "season" = '2002–03' AND "opponent" = 'zenit st. petersburg'

Question: What is the Round when the series shows 5th place, and a Season of 2006–07?
SQL: SELECT "round" FROM grasshopper_zurich_matches WHERE "series" = '5th place' AND "season" = '2006–07'

Question: What is the Series for the uefa cup, in the 2006–07 season, and a Round of group, and an opponent of az?
SQL: SELECT "series" FROM grasshopper_zurich_matches WHERE "competition" = 'uefa cup' AND "season" = '2006–07' AND "round" = 'group' AND "opponent" = 'az'