Oracle分组取第一条数据

对多数据进行分组排序后取每组第一条记录

 

SELECT *
  FROM (SELECT ROW_NUMBER() OVER(PARTITION BY <PK_FINANCE_ACCOUNT_1> ORDER BY <amassdate> DESC) LEV,
               <hx_amass_liquid>.*
          FROM <hx_amass_liquid>)
 WHERE LEV = 1
 ORDER BY <PK_FINANCE_ACCOUNT_2> DESC

 

<PK_FINANCE_ACCOUNT_1> -- 分组列 

 

<amassdate> -- 排序列

 

<hx_amass_liquid> -- 表名

 

<PK_FINANCE_ACCOUNT_2> -- 排序列

 

注：<hx_amass_liquid>.* -- 一定要有表名，否则会报“缺失表达式”错误

 

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分组时不仅想取每组的第一条记录，还想取每组共有几条记录

SELECT *
FROM (

SELECT ROW_NUMBER() OVER(PARTITION BY PK_FINANCE_ACCOUNT ORDER BY amassdate DESC) LEV,
            

             count(0) over(partition by PK_FINANCE_ACCOUNT) cnt,

             

             hx_amass_liquid.*
 FROM

 hx_amass_liquid

)

 WHERE LEV = 1
 ORDER BY PK_FINANCE_ACCOUNT DESC

评论

1 楼 wing123 2013-03-14  

例2:

SELECT * FROM(
SELECT z.type , z.code ,ROW_NUMBER()
OVER(PARTITION BY z.type ORDER BY z.code) AS code_id
FROM group_info z
)
WHERE code_id =1;