Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_69549 ( "Year" real, "Men's singles" text, "Women's singles" text, "Men's doubles" text, "Women's doubles" text, "Mixed doubles" text )

### Question ###
What players played mixed doubles when zhang xi played mixed singles?

### Accurate SQL ###

SELECT "Mixed doubles" FROM table_69549 WHERE "Women's singles" = 'zhang xi'