CREATE TABLE table_28138035_6 (womens_doubles VARCHAR2, womens_singles VARCHAR2, mens_singles VARCHAR2)

How many times did li ju win the womens singles and wang liqin win the mens singles?
SELECT COUNT(womens_doubles) FROM table_28138035_6 WHERE womens_singles = "Li Ju" AND mens_singles = "Wang Liqin"
SELECT COUNT("womens_doubles") FROM "table_28138035_6" WHERE "Li Ju" = "womens_singles" AND "Wang Liqin" = "mens_singles"