数据准备去重处理计算总和输出结果 总结 在MySQL中使用窗口函数SUM() OVER()来计算聚合值时,避免重复累加的核心在于合理使用DISTINCT来去重。通过创建临时表,我们可以确保每一组数据的唯一性,从而正确地进行总和计算。虽然在某些情况下可能需要考虑性能和执行效率,但这种方法通常是处理相同数量值累加问题的一种有效方案。
select * from #T a where ID in(select min(ID) from #T group by Name) --SQL2005: 方法: select ID,Name,Memo from (select *,min(ID)over(partition by Name) as MinID from #T a)T where ID=MinID 方法: select ID,Name,Memo from (select *,row_number()over(partition by Name order...
t2.gmt_create, t3.gmt_modified, t3.share_num, ROW_NUMBER()OVER(PARTITIONBYt3.`staff_id`,t3.`article_id`ORDERBYt3.id )asrowNum, t2.view_num, t2.user_id, ROW_NUMBER()OVER(PARTITIONBYt2.`user_id`,t2.`staff_id`,t2.`article_id`,t2.`day`ORDERBYt2.id )asrowNum2, t4.nick...
SUM([ DISTINCT | UNQIUE | ALL ] expr) [ OVER (analytic_clause) ] 参数解释 参数说明 DISTINCT | UNQIUE | ALL 计算时是否去重。为可选项,默认值 ALL。 ALL:计算所有值,包含重复行,且忽略值为 NULL 的行。 DISTINCT:去除重复行,且忽略值为 NULL 的行。 UNIQUE:去除重复行,且忽略值为 NULL 的行...
ROWNUMBER() OVER( PARTITION BY COL1 ORDER BY COL2)用法,先分组,然后在组内排名,分组计算,主表与附表一对多取唯一等 2016-03-17 13:42 − ROWNUMBER() OVER( PARTITION BY COL1 ORDER BY COL2)用法 今天在使用多字段去重时,由于某些字段有多种可能性,只需根据部分字段进行去重,在网上看到了rownumber...
6 a,5 b, 3 c FROM dual unionSELECT 7 a,2 b, 3 c FROM dual unionSELECT 7 a,2 b, 8 c FROM dual unionSELECT 9 a,3 b, 3 c FROM dual )SELECT a,b,c,sum(c) over( partition by b ) partition_sum,sum(c) over( partition by b order by a desc) partition_order_sum FROM ...
5、count(DISTINCT epr1) 对该字段去重去null的计数,count(epr1) 对该字段去null的计数 6、row_number() OVER (partition BY epr1, epr2 ORDER BY epr3 DESC) as number 先对epr1、epr2两个字段聚合数据然后在按epr3排序,按自然数顺序往下排,epr3相同比较数据的顺序,递增 ...
SUM(SUM(IF(if_follow = 2, -1, if_follow))) OVER (PARTITION BY author ORDER BY DATE_FORMAT(start_time, '%Y-%m')) total_fans FROM tb_video_info LEFT JOIN tb_user_video_log USING(video_id) WHERE YEAR(start_time) = 2021
(select id,date_sub(time,INTERVAL cum day) as base_time ,count(*) as co #计数 from (select *,row_number() over(PARTITION by id order by time) as cum #按照用户id进行分组,按照登录日期dt进行排序 from (select DISTINCT id,date(date) as time from tb order by id #用户登录日期dt去重 ...
"select [col0], [col1], [col2], [col3], [col4], [col5], [col6] from tb_histstatus...