CREATE TABLE table_10023387_1 (singles_w_l VARCHAR, player VARCHAR)

what's the singles w-l for kim doo-hwan
SELECT singles_w_l FROM table_10023387_1 WHERE player = "Kim Doo-Hwan"
SELECT "singles_w_l" FROM "table_10023387_1" WHERE "Kim Doo-Hwan" = "player"