Table: game_seven_1991
Columns: year
winning_team
losing_team
score
site

Question: When has a Site of tainan city and a Score of 8–6?
SQL: SELECT "year" FROM game_seven_1991 WHERE "site" = 'tainan city' AND "score" = '8–6'

Question: Which Score that has a Winning team of wei chuan dragons?
SQL: SELECT "score" FROM game_seven_1991 WHERE "winning_team" = 'wei chuan dragons'