row_number() over(PARTITION by 某某字段 order by 排序字段) as rn from table 例子: select * from ( select *, row_number() over(PARTITION by 某某字段 order by 排序字段) as rn from table )as t1 where t1.rn = 1
row_number() over(partition by xxxx order by xxx) 在获取数据时order by 会被截取,最终解析的sql就报错了,烦请波总测一下,谢谢! jian23cn创建了任务3个月前 杜福忠3个月前 使用paginateByFullSql 文档的最后几行:https://jfinal.com/doc/5-6 ...
第一、row_number() over(partition by 首先要了解下oracle中这个函数的用法,看个例子 select t.*,row_number() over(partition by t.owner order by y.createDate desc) rn from test t 1. 这个语句的意思就是,把test这个表的数据按照owner 分组并且给每个分组的里面的数据加上一个序列号,数据格式如下 i...
使用DISTINCT 关键字进行去重: SELECT DISTINCT column1, column2 FROM table_name ORDER BY column1, column2; 复制代码 使用ROW_NUMBER() 窗口函数进行去重排序: SELECT column1, column2 FROM ( SELECT column1, column2, ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY column1, column2...
假设你的实时数据表名为real_time_data,设备标识字段为device_id,时间戳字段为timestamp。 编写SQL查询: 你可以使用窗口函数ROW_NUMBER()来为每个设备的记录按时间戳排序,并获取最新的记录。 sql SELECT * FROM ( SELECT *, ROW_NUMBER() OVER (PARTITION BY device_id ORDER BY timestamp DESC) AS rn FROM...
2.PARTITION by :对arch_id 这个字段进行分组 3.ORDER BY:在分组区间内按year_month 进行倒序 步骤二:筛选出最大记录 在原查询结果中筛选出idx第一条,即为最大记录。 以上调整后的sql语句如下: SELECT * FROM ( SELECT tb.curr_read,tb.arch_id,ROW_NUMBER() OVER(PARTITION by arch_id ORDER BY year...
pgsql取关联表中的较大值 SELECT * from ( SELECT ROW_NUMBER() OVER(PARTITION by wj ORDER BY px desc)idx,px,wj from table ) ord where ord.idx = 1 wj :关联外键 px :排序字段 ROW_NUMBER:该函数可以对分组进行编号 PARTITION by :对wj这个字段进行分组...
SELECT ROW_NUMBER() OVER (partition by discontinued_log.park_code ORDER BY discontinued_log.time desc) AS rownum, from discontinued_log ) as te where te.rownum <2 略微讲解: partition by discontinued_log.park_code discontinued_log.park_code这个是要分组的字段 ...
简介:PgSQL——查询某字段每个月的排名 select ny, dense_rank() over (partition by ny, gfbm order by zpf desc) as pm from table;select ny, rank() over (partition by ny, gfbm order by zpf desc) as pm from table;select ny, row_number() over (partition by ny, gfbm order by zpf de...
SELECT max(len)over(partition by road_id) param from rs; -- row_number() over(partition by ... order by ...) SELECT row_number() over(partition by road_id) param,road_id from rs; -- rank() over(partition by ... order by ...) ...