SQL 在相关 Table 中查找最近的生效日期

Question

我会先说明这个问题与 SQL Join on Nearest Less Than Date 类似，但那里的解决方案不适用于我的问题。我不需要选择单个列，而是需要 table 的结果，即基于最近日期的 'filtered'。

我有三个 table。主要 table 包含以下形式的时间票数据：

ticketId 
ticketNumber 
ticketDate
projectId

辅助 table 跟踪项目每张每日票证上的资源费率表。它看起来像这样：

scheduleId
projectId
effectiveDate

还有第三个 table 与实际包含适用费率的第二个相关。像这样：

scheduleId
straightTime
overTime

加入 projectId 上的前两个 table（显然）会复制项目费率表中每条记录的数据。如果我有 3 个项目 1 的费率表，那么工单记录会产生如下结果：

 ticketNumber  | ticketDate   | projectId   | effectiveDate  | scheduleId
 ------------- | ------------ | ----------- | -------------- | ----------
 1234          | 2016-06-18   | 25          | 2016-06-01     | 1
 1234          | 2016-06-18   | 25          | 2016-06-15     | 2
 1234          | 2016-06-18   | 25          | 2016-06-31     | 3

在我的结果中选择有效日期很简单，示例如下：

  SELECT *
    ,  (SELECT TOP 1 t1.effectiveFrom 
        FROM         dbo.labourRateSchedule t1
        WHERE        t1.effectiveFrom <= t2.[date] and t1.projectId = t2.projectId
        ORDER BY     t1.effectiveFrom desc) as effectiveDate

  FROM dbo.timeTicket t2
  ORDER BY t.date

但是，我需要能够将 dbo.labourRateSchedule 的 ID 加入第三个 table 以获得适用的实际费率。将 t1.ID 添加到 SELECT 语句不会使其可访问到另一个相关的 table.

我一直在尝试在 FROM 语句中加入 SELECT 语句，但结果只是最后一个 effectiveDate 值，而不是最接近适用的 ticketDate 的值。

我将不胜感激任何帮助！

Answer 1

你能试试这样吗（你应该改变一些东西，因为你没有 post 所有信息）。

 SELECT A.*, C.*
  FROM timeTicket A
  INNER JOIN  (SELECT * , ROW_NUMBER() OVER (PARTITION BY projectId ORDER BY effectiveFrom DESC) AS RN
                FROM labourRateSchedule) B ON A.projectId=B.projectId AND B.RN=1
  INNER JOIN YOUR3TABLE C ON B.SCHEDULEID=C.SCHEDULEID

Answer 2

你可以通过 CTE 和 Rank 函数来做到这一点 -

create table timeTicket  (ticketId  int,
ticketNumber int ,
ticketDate smalldatetime ,
projectId int )
go

create table labourRateSchedule 
(scheduleId int,
projectId int,
effectiveDate smalldatetime ) 
go

create table ApplicableRates
(scheduleId int,
straightTime smalldatetime ,
overTime smalldatetime) 
go

insert into timeTicket
select 1 , 1234   ,'2016-06-18' ,25   
go

insert into labourRateSchedule
select 1 , 25   ,'2016-06-01'   
union all select 2 , 25   ,'2016-06-15'  
union all select 3 , 25   ,'2016-06-30'  
go

insert into ApplicableRates    
select 1 , '2016-06-07'    ,'2016-06-07'   
union all select 2 ,  '2016-06-17'      ,'2016-06-17'  
union all select 3 ,   '2016-06-22'     ,'2016-06-25'           
go

  with cte 
  as (
  select t1.ticketNumber    ,t1.ticketDate  ,t1.projectId       ,t2.effectiveDate   ,t3.scheduleId  ,t3.straightTime    
  ,t3.overTime , rank() over (  partition by t1.ticketNumber order by abs     (DATEDIFF(day,t1.ticketDate, t2.effectiveDate) ) )  DyaDiff 
  from  timeTicket t1 join  labourRateSchedule t2
  on t1.projectId = t2.projectId
  join ApplicableRates t3
  on t2.scheduleId = t3.scheduleId)
  select * from cte where DyaDiff = 1

Answer 3

您可以使用 CROSS APPLY:

将子查询移动到 FROM 子句

SELECT *
FROM dbo.timeTicket tt
CROSS APPLY
(
  SELECT TOP(1) *
  FROM dbo.labourRateSchedule lrs
  WHERE lrs.projectId = tt.projectId
    AND lrs.effectiveFrom <= tt.date
  ORDER BY lrs.effectiveFrom desc
) best_lrs
JOIN dbo.schedule s on s.schedule_id = best_lrs.schedule_id
ORDER BY tt.date

SQL 在相关 Table 中查找最近的生效日期

SQL Find Nearest Effective Date in Related Table

sql

database

sql-server

join

sql-server-2016