Question: How many years did Peter Mikkelsen win the Mens Singles?
SQL: SELECT COUNT("Year") FROM "1-12164707-1" WHERE "Mens singles" = 'Peter Mikkelsen';

Question: Who won the Men's Doubles when Karina de Wit won the Women's Singles?
SQL: SELECT "Mens doubles" FROM "1-12164707-1" WHERE "Womens singles" = 'Karina de Wit';

Question: How many Mixed Doubles won when Oliver Pongratz won the Men's Singles?
SQL: SELECT COUNT("Mixed doubles") FROM "1-12164707-1" WHERE "Mens singles" = 'Oliver Pongratz';

Question: Who won the Men's Doubles when Guo Xin won the Women's Singles?
SQL: SELECT "Mens doubles" FROM "1-12164707-1" WHERE "Womens singles" = 'Guo Xin';