select *, 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
获取每个科目的最低分 postgres=#select*from(select*,row_number()over(partitionbycourseorderbyscoreasc)rnfromstudent) tempwheretemp.rn=1; id|name|course|score|rn---+---+---+---+---15|黎明|化学|78|13|周润发|外语|67|112|黎明|数学|65|19|周星驰|物理|68|111|黎明|语文|85|1...
获取每个科目的最低分 postgres=# select * from (select *,row_number() over(partition by course order by score asc)rn from student) temp where temp.rn=1; id | name | course | score | rn ---+---+---+---+--- 15 | 黎明 | 化学 | 78 | 1 3 | 周润发 | 外语 | 67 | 1 1...
数据库:pgsql SQL语句示例: select * from ( select row_number() over(partition by item_id,loc_code order by batch_num) as sn,ten_code,whs_code,cli_code,item_code,item_id,loc_code from mytable ) tbl row_number() over(partition by xxxx order by xxx) 在获取数据时order by 会被截取,...
ROW_NUMBER() OVER (PARTITION BY mc ORDER BY gid) AS rn FROM tablename sub1 WHERE EXISTS ( SELECT 1 FROM tablename sub2 WHERE sub1.mc = sub2.mc AND sub1.gid <> sub2.gid AND SQRT(POWER(sub1.lng - sub2.lng, 2) + POWER(sub1.lat - sub2.lat, 2)) < 0.0001 ...
2.2 partition <!-- 临时数据表 --> with tmp_data as ( select split_part(line,'_',1) stu_id, split_part(line,'_',2) stu_name, split_part(line,'_',3) stu_score, split_part(line,'_',4) stu_class_id from ( select
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 ...
使用ROW_NUMBER()窗口函数进行去重 如果你需要基于某些列(如email)保留每个重复组中的一条记录,你可以使用ROW_NUMBER()窗口函数结合CTE(公用表表达式)或子查询来实现。 sql WITH RankedStudents AS ( SELECT id, name, email, ROW_NUMBER() OVER (PARTITION BY email ORDER BY id) AS rn FROM students ) DEL...
DELETE FROM table_name WHERE id IN ( SELECT id FROM ( SELECT id, ROW_NUMBER() OVER (PARTITION BY column1, column2, ... ORDER BY id) AS rnum FROM table_name ) t WHERE t.rnum > 1 ); 复制代码在上面的语句中,column1, column2, ...是用来识别重复数据的列,id是表的主键字段。
在上面的示例中,ROW_NUMBER() 函数会为查询结果集中的每一行分配一个唯一的行号,并根据 column1 列的值对行进行排序。您可以根据需要更改 ORDER BY 子句来指定不同的排序条件。 请注意,ROW_NUMBER() 函数必须与 OVER 子句一起使用,以便指定排序条件。您还可以选择使用 PARTITION BY 子句来分组数据,并在每个分组...