欄位1  欄位2  欄位3 
 1      a       A
 2      a       B
 3      b       V
 4      b       F
 5      c       O
 6      d       G

類似上邊的表，現在想去重查詢出欄位2所有值，然後按欄位1排序，應該怎麼寫sql語句？
結果出來應該是：
a
b
c
d

1)

select * from (select max(欄位1) as 欄位1,欄位2 from 表 group by 欄位2)t order by 欄位1

2)

SELECT A.* FROM 表 A JOIN 
(
SELECT MIN(欄位1) AS 欄位1,欄位2 FROM 表 GROUP BY 欄位2 
) B ON (A.欄位1=B.欄位1 AND A.欄位2=B.欄位2) 
ORDER BY A.欄位1