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oracle 指定字段排序并去重?

oracle 指定字段排序并去重?

三國紛爭 2018-08-14 11:09:17
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(shí)獲取userid,status,order的值。想要的結(jié)果為uesrid | status    |    order111    | 0         |    9222    | 2         |    4333    | 3         |    10SELECT * FROM (SELECT * FROM `logs` ORDER BY `order` DESC) AS a GROUP BY a.userid;在mysql下,可以通過以下SQL獲得。但是oracle這么寫語法就報(bào)錯,請問oracle該如何實(shí)現(xiàn)?
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2 回答

?
交互式愛情

TA貢獻(xiàn)1712條經(jīng)驗(yàn) 獲得超3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) 2018-08-26
?
函數(shù)式編程

TA貢獻(xiàn)1807條經(jīng)驗(yàn) 獲得超9個贊

用開窗函數(shù)就可以呀:

https://img1.sycdn.imooc.com//5b8241410001f46603160191.jpg

https://img1.sycdn.imooc.com//5b824141000105ba07840379.jpg


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反對 回復(fù) 2018-08-26
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