row_number( )over(partition by user_id order by date)

行号函数 `row_number()` 在 SQL 中被用来为每个分区中的行分配唯一的行序号。当你在查询中使用 `OVER` 子句，并结合 `PARTITION BY` 和 `ORDER BY` 时，这个函数会对指定的列（这里是 `user_id`）进行分组，然后按照另一个列（这里是 `date`）对每组内的行进行排序。

具体来说，`row_number() over (partition by user_id order by date)` 的含义是：

- `partition by user_id`: 将数据集按照 `user_id` 列分成多个子集，每个子集包含具有相同用户ID的记录。
- `order by date`: 在每个 `user_id` 分区内，根据 `date` 列的值对行进行升序或降序排列。
- `row_number()` 函数会为每个分区中的每一行分配一个行号，从 1 开始，对于分区中最早的日期行分配第一个行号（通常是 1），随后的行递增。

这样，对于每个用户，你可以通过 `row_number()` 来跟踪他们历史记录中的事件顺序，这对于数据分析和报告非常有用。如果你有一个表，你想查看每个用户的交易时间序列，就可以方便地获取每个交易发生的顺序。

相关问题

select t.id,t.amount from( select row_number() over(partition by amount) rn from users u join orders o on u.id=o.id desc)t where rn <=10

这是一个 SQL 查询语句，它的作用是从用户表和订单表中获取用户 ID 和订单金额，并按照订单金额分组，然后取每组中排名前 10 的记录的 ID 和金额。具体实现可以参考以下代码：

SELECT t.id, t.amount
FROM (
  SELECT 
    u.id,
    o.amount,
    ROW_NUMBER() OVER (PARTITION BY o.amount ORDER BY o.order_date DESC) AS rn
  FROM users u
  JOIN orders o ON u.id = o.user_id
) t
WHERE t.rn <= 10;

需要注意的是，这个查询语句可能存在一些性能问题，因为它需要使用窗口函数和子查询。如果数据量很大，可能需要优化查询计划。

select b.[leader_name],[inspected_person],wrong_type,b.Departure_date,count(*) as miss数量 from ( select * from ( select * ,row_number() over(partition by [check_date],[checker],[inspected_person],[secondary_rework],[type],[project],[project_name],[NID],[wrong_type],[reason],[wrong_description],[complaint_status],[date],[create_time] order by [inspected_person] desc) as row from ( SELECT [check_date] ,[checker] ,[inspected_person] ,[secondary_rework] ,[type] ,[project] ,[project_name] ,[NID] ,[wrong_type] ,[reason] ,[wrong_description] ,[complaint_status] ,[date] ,[create_time] ,[AssigneeId] FROM [DV_report].[dbo].[miss] as a left join [User] as b on a.[AssigneeId]=b.id where date>='${start}' and date<='${end}' and complaint_status='申诉后' and wrong_type not in ('无','建议') and inspected_person not in('DL001','DL002') ) c) d where d.row = '1' UNION select * from ( select * ,row_number() over(partition by [check_date],[checker],[inspected_person],[secondary_rework],[type],[project],[project_name],[NID],[wrong_type],[reason],[wrong_description],[complaint_status],[date],[create_time] order by [inspected_person] desc) as row from ( SELECT [check_date] ,[checker] ,[secondary_rework] as [inspected_person] ,'' as [secondary_rework] ,[type] ,[project] ,[project_name] ,[NID] ,[wrong_type] ,[reason] ,[wrong_description] ,[complaint_status] ,[date] ,[create_time] ,[AssigneeId] FROM [DV_report].[dbo].[miss] as a left join [User] as b on a.[AssigneeId]=b.id where date>='${start}' and date<='${end}' and complaint_status='申诉后' and wrong_type = '网络问题' and [reason] = '状态错误' and [secondary_rework] is not null and [secondary_rework] !='' and inspected_person not in('DL001','DL002') ) c) d where d.row = '1' )as a left join [User] as b on a.[AssigneeId]=b.id WHERE b.leader_name IS NOT NULL and b.IsActive = '1' group by b.[leader_name],[inspected_person],wrong_type,b.Departure_date order by [inspected_person] 帮我将这段代码转换为postgre格式语言

SELECT b."leader_name", "inspected_person", "wrong_type", b."Departure_date", count(*) as miss数量
FROM (
SELECT *
FROM (
SELECT *, row_number() OVER(PARTITION BY "check_date","checker","inspected_person","secondary_rework","type","project","project_name","NID","wrong_type","reason","wrong_description","complaint_status","date","create_time" ORDER BY "inspected_person" DESC) AS row
FROM (
SELECT "check_date"
,"checker"
,"inspected_person"
,"secondary_rework"
,"type"
,"project"
,"project_name"
,"NID"
,"wrong_type"
,"reason"
,"wrong_description"
,"complaint_status"
,"date"
,"create_time"
,"AssigneeId"
FROM "DV_report"."dbo"."miss" AS a
LEFT JOIN "User" AS b ON a."AssigneeId"=b.id
WHERE "date">='${start}'
AND "date"<='${end}'
AND "complaint_status"='申诉后'
AND "wrong_type" NOT IN ('无','建议')
AND "inspected_person" NOT IN('DL001','DL002')
) c
) d
WHERE d.row = '1'
UNION
SELECT *
FROM (
SELECT *, row_number() OVER(PARTITION BY "check_date","checker","inspected_person","secondary_rework","type","project","project_name","NID","wrong_type","reason","wrong_description","complaint_status","date","create_time" ORDER BY "inspected_person" DESC) AS row
FROM (
SELECT "check_date"
,"checker"
,"secondary_rework" AS "inspected_person"
,'' AS "secondary_rework"
,"type"
,"project"
,"project_name"
,"NID"
,"wrong_type"
,"reason"
,"wrong_description"
,"complaint_status"
,"date"
,"create_time"
,"AssigneeId"
FROM "DV_report"."dbo"."miss" AS a
LEFT JOIN "User" AS b ON a."AssigneeId"=b.id
WHERE "date">='${start}'
AND "date"<='${end}'
AND "complaint_status"='申诉后'
AND "wrong_type" = '网络问题'
AND "reason" = '状态错误'
AND "secondary_rework" IS NOT NULL
AND "secondary_rework" !=''
AND inspected_person NOT IN('DL001','DL002')
) c
) d
WHERE d.row = '1'
) AS a
LEFT JOIN "User" AS b ON a."AssigneeId"=b.id
WHERE b."leader_name" IS NOT NULL
AND b."IsActive" = '1'
GROUP BY b."leader_name","inspected_person","wrong_type",b."Departure_date"
ORDER BY "inspected_person"