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oracle 指定字段排序并去重?

oracle 指定字段排序并去重?

GCT1015 2018-07-22 14:18:05
有l(wèi)ogs表的結(jié)構(gòu)為uesrid | status    |    order111    | 5         |    7111    | 0         |    9111    | 1         |    8222    | 3         |    3222    | 1         |    2222    | 2         |    4333    | 3         |    10請問如何先以order desc排序,并通過userid去重,同時獲取userid,status,order的值。想要的結(jié)果為uesrid | status    |    order111    | 0         |    9222    | 2         |    4333    | 3         |    10在mysql下,可以通過以下SQL獲得。SELECT * FROM (SELECT * FROM `logs` ORDER BY `order` DESC) AS a GROUP BY a.userid;但是oracle這么寫語法就報錯,請問oracle該如何實現(xiàn)?
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3 回答

?
慕娘9325324

TA貢獻1783條經(jīng)驗 獲得超5個贊

WITH temp as

    (

    select '111' as userid,'5' as status,'7' as ord from dual

    union all

    select '111' as userid,'0' as status,'9' as ord from dual

    union all

    select '111' as userid,'1' as status,'8' as ord from dual

    union all

    select '222' as userid,'3' as status,'3' as ord from dual

    union all

    select '222' as userid,'1' as status,'2' as ord from dual

    union all

    select '222' as userid,'2' as status,'4' as ord from dual

    union all

    select '333' as userid,'3' as status,'10' as ord from dual

    )

select userid,status,ord from (    

select userid,status,ord,row_number() over(partition by userid order by ord desc)  rn 

from temp

)

where rn=1

;


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反對 回復(fù) 2018-07-25
?
撒科打諢

TA貢獻1934條經(jīng)驗 獲得超2個贊

用開窗函數(shù)就可以呀:

https://img1.sycdn.imooc.com//5b587ade0001f46603160191.jpg

https://img1.sycdn.imooc.com//5b587adf000105ba07840379.jpg


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反對 回復(fù) 2018-07-25
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