Alex Nikolic มาจากกี่สัญชาติ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
How many nationalities does Alex Nikolic come from?It is not neccessary to use all the tables.
 table_2897457_7:  (nationality [ VARCHAR ] player [ VARCHAR) ]
SELECT COUNT(nationality) FROM table_2897457_7 WHERE player = "Alex Nikolic"