SQL查詢，我錯了嗎？

Question

我想爲任何給定的城市提取不同的City姓名和一個郵政編碼。

zip city state 
00603 AGUADILLA PR 
00604 AGUADILLA PR 
00605 AGUADILLA PR 

查詢：

SELECT DISTINCT (city),(zip) 
    FROM zips 
WHERE state = 'PR' 

我試着GROUP BY子句爲好，讓我知道我錯了這裏。

Answer 1

select city, max(zip) 
from zips 
where state='PR' 
group by city 

Answer 2

SELECT city, max(zip) from zips where state='PR' group by city, state