Table: badminton_results
Columns: year
mens_singles
womens_singles
mens_doubles
womens_doubles
mixed_doubles

Question: Who won the womens doubles when wu jianqui won the womens singles?
SQL: SELECT "womens_doubles" FROM badminton_results WHERE "womens_singles" = 'Wu Jianqui'

Question: Who won the mixed doubles when ji xinpeng won the mens singles?
SQL: SELECT "mixed_doubles" FROM badminton_results WHERE "mens_singles" = 'Ji Xinpeng'

Question: How many womens singles winners were there when peter rasmussen won the mens singles?
SQL: SELECT COUNT("womens_singles") FROM badminton_results WHERE "mens_singles" = 'Peter Rasmussen'