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create table test_db (

  id number,
  name varchar2(10),
  count number,
  logdate date

)

¼ÙÉèÓÐÕâЩ¸öÊý¾Ý:

1,a1,1,2010-02-03
2,a2,2,2010-02-03
.................
10,a10,10,2010-02-03
11,a11,11,2010-02-03
..............
30,a3,3,2010-02-04
31,a5,7,2010-02-04
............

101,a2,10,2010-02-08


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..........

select id, name, count, logdate from (select test_db.*,row_number() over(partition by logdate order by logdate) rn from test_db) where rn < 11; 


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select id, name, count, logdate from (select test_db.*,row_number() over(partition by logdate order by logdate) rn from test_db) where rn <= 10;

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SQL code:
select *
from test_db t
where 10>(select count(*) from test_db where logdate=t.logdate and count>t.count);


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