Who is listed under mens singles when the year location is 2009 doha?
CREATE TABLE "table1_28138035_27" (
  "year_location" text,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text
);
SELECT "mens_singles" FROM "table1_28138035_27" WHERE "year_location"='2009 Doha';