Oracle在查询中获得唯一的年份和月份

Question

我有以下查询返回我正在寻找的结果,除了事实我无法分组工作:

select EXTRACT(month from datetime_insert) m, 
       EXTRACT(year from datetime_insert) y 
  from tst_result_main 
 order by datetime_insert

返回以下内容:

m    y
1    2006
1    2006
2    2006
2    2006
2    2007
2    2007

结果我正在寻找:

m    y
1    2006
2    2006
2    2007

我试过以下哪个抛出错误:

select EXTRACT(month from datetime_insert) m,
       EXTRACT(year from datetime_insert) y 
  from tst_result_main 
 order by datetime_insert group by y, m

错误:

ORA-00933:SQL命令未正确结束00933. 00000 - "SQL命令未正确结束"*原因:
*操作:行错误:7列:136

任何帮助,将不胜感激

Answer 1

你尝试过类似DISTINCT值的东西:

select DISTINCT
    EXTRACT(month from datetime_insert) m
    , EXTRACT(year from datetime_insert) y 
    from tst_result_main