例子来源:http://hi.baidu.com/ljw460/blog/item/335d86526e0e70080cf3e3b9.html
table表字段1 字段2
id name
1 a
2 b
3 c
4 c
5 b为什么我按照这个例子却出不来结果???
select *, count(distinct name) from table group by name
table表字段1 字段2
id name
1 a
2 b
3 c
4 c
5 b为什么我按照这个例子却出不来结果???
select *, count(distinct name) from table group by name
hr@ORCL> select * from
2 (select id,name,rank() over(partition by name order by id) m from t)
3 where m=1; ID NAME M
---------- ----- ----------
1 a 1
2 b 1
3 c 1
WITH t AS(
SELECT 1 id,'a' NAME FROM dual
UNION ALL
SELECT 2,'b' FROM dual
UNION ALL
SELECT 3,'c' FROM dual
UNION ALL
SELECT 4,'c' FROM dual
UNION ALL
SELECT 5,'b' FROM dual
)
SELECT Min(id)id,NAME FROM t GROUP BY name