如何根据列获得上限值

Question

我有一个 table 测试，有票和车辆。

ticket  vehicle
1000    101
1001    102
1002    102
1003    103
1004    104
1005    102
1006    102

我的要求：输入将是车票，输出将是vehicle.If 车辆在重复，那么我必须只获得前一张车票。

例如：票1006有车辆102即repeating.I表示1006,1005,1002,1001票有车辆102.So如果输入是1006 则输出为 1005。同样，如果输入为 1005，则输出将为 1002.And 如果输入为 1002，则输出将为 1001。我喜欢这个

SELECT ticket
FROM (SELECT ROW_NUMBER() OVER (ORDER BY ticket desc) AS RowNumber, *
      FROM test
      WHERE vehicle = (SELECT vehicle FROM test WHERE ticket = 1005)) AS getsecondsLast
WHERE RowNumber = 2

但这只有在输入为 1006 时才能正常工作。

请帮帮我fiddle here

Answer 1

类似于：

Select *
from test outer_test
outer apply 
(select max(ticket) as Previous_Ticket from 
 test inner_test 
 where inner_test.vehicle = outer_test.vehicle
 and outer_test.ticket > inner_test.ticket) previous

http://sqlfiddle.com/#!6/ca9cd/69/0

Answer 2

SQL Fiddle

MS SQL Server 2014 架构设置:

create table test(
  ticket int,vehicle int);
  insert into test values(1000,101);
  insert into test values(1001,102);
  insert into test values(1002,102);
  insert into test values(1003,103);
  insert into test values(1004,104);
    insert into test values(1005,102);
  insert into test values(1006,102);

查询 1:

declare @ticket int = 1005;

select top(1) T1.ticket
from dbo.test as T1
where T1.ticket < @ticket and
      T1.vehicle in (
                    select T2.vehicle
                    from dbo.test as T2
                    where T2.ticket = @ticket
                    )
order by T1.ticket desc;

Results:

| ticket |
|--------|
|   1002 |

Answer 3

http://sqlfiddle.com/#!6/ca9cd/22

DECLARE @ticket int = 1006

select MAX(prev.ticket) from test curr
inner join test prev
on curr.vehicle = prev.vehicle
  AND curr.ticket > prev.ticket
where curr.ticket = @ticket

Answer 4

这是另一种方式：

如果 Vehicle 没有重复，这将 return 原始票。

DECLARE @ticket INT = 1002

;WITH CteUnion AS(
    SELECT *
    FROM Test
    WHERE
        Ticket = @ticket
    UNION ALL
    SELECT *
    FROM Test
    WHERE
        Vehicle = (SELECT Vehicle FROM Test WHERE Ticket = @ticket)
        AND Ticket < @ticket

),
CteNumbered AS(
    SELECT *,
        RN =
            ROW_NUMBER() OVER(
                ORDER BY 
                    CASE 
                        WHEN Ticket = @ticket THEN -1
                        ELSE Ticket
                    END
                DESC
            )
    FROM CteUnion
)
SELECT Ticket, Vehicle
FROM CteNumbered
WHERE RN = 1

SQL Fiddle

Answer 5

这样你就可以得到你想要的答案。

看看这个fiddle

查询：

Select ticket, vehicle, (Case When Output IS NULL Then ticket else Output End) As PrevTicket
from test t1
outer apply (select max(ticket) as Output from test t2 
where t1.vehicle = t2.vehicle and t2.ticket < t1.ticket) t3

您可以在此处添加 Where 条件以获得特定工单的输出。

Where ticket = 1005

Answer 6

我认为这是最简单的方法（如果车辆只有一张票，那么 return 票号为空）

DECLARE @ticket int = 1006

SELECT TOP 1 t2.ticket, t1.vehicle
FROM test t1 LEFT JOIN test t2 ON(t1.vehicle = t2.vehicle AND t2.ticket < t1.ticket)
WHERE t1.ticket = @ticket
ORDER BY t2.Ticket DESC

如何根据列获得上限值

How to get just upper value based on column

sql

sql-server

sql-server-2012