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
SELECT dense_rank()over(partition by road_id ORDER BY len) param,road_id from rs; -- count() over(partition by ... order by ...) SELECT count() over(partition by road_id) param,road_id from rs;
1.ROW_NUMBER:该函数可以对分组进行编号 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() OV...
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 desc) as pm from table; 1. 2. 3...
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() 窗口函数进行去重排序: SELECTcolumn1, column2FROM(SELECTcolumn1, column2,ROW_NUMBER()OVER(PARTITIONBYcolumn1, column2ORDERBYcolumn1, column2)ASrnFROMtable_name ) subWHERErn=1ORDERBYcolumn1, column2; 这样可以按照指定的列进行排序,并去除重复值。
SELECT id, ROW_NUMBER() OVER( PARTITION BY fruit ORDER BY id ) AS row_num FROM basket ) t WHERE t.row_num > 1 ); 子查询返回重复行,除了重复记录的第一行;然后外部 DELETE 根据子查询删除对应记录。 如果你想保留最高 ID 记录,需要修改排序条件: ...
select(selectrelnameascommentfrompg_classwhereoid=a.attrelid)astable_name,row_number()over(partitionby(selectrelnameascommentfrompg_classwhereoid=a.attrelid)orderbya.attnum), a.attnameascolumn_name, format_type(a.atttypid,a.atttypmod)asdata_type, ...
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...