Question

我无法弄清楚如何开始此查询。

我有一个包含以下列和数据的表：

User   BeginMile EndMile
1         1        5
1         5        6
1         6        20
1         20       25
1         25       29
2         1         9
2         15        20
3         1         2
3         6         10
3         10        12

我需要首先找到每个用户从前一条记录的EndMile到下一条记录的BeginMile的间隙。然后，我需要在每个用户发生间隙之前和之后返回记录。

在上一个数据示例中，我希望返回以下内容：

User   PrevBeginMile   PrevEndMile    AfterBeginMile AfterEndMile   Gap
2         1                9                15          20           6
3         1                2                6           10           4

如何做到这一点？

Answer 1

考虑到你在使用SQL 2005，这应该可行：

DECLARE @Runners TABLE (Id INT, BeginMile INT, EndMile INT)

INSERT INTO @Runners VALUES (1,1,5)
INSERT INTO @Runners VALUES (1,5,6)
INSERT INTO @Runners VALUES (1,6,20)
INSERT INTO @Runners VALUES (1,20,25)
INSERT INTO @Runners VALUES (1,25,29)
INSERT INTO @Runners VALUES (2,1,9)
INSERT INTO @Runners VALUES (2,15,20)
INSERT INTO @Runners VALUES (3,1,2)
INSERT INTO @Runners VALUES (3,6,10)
INSERT INTO @Runners VALUES (3,10,12)

WITH OrderedUsers AS (
    SELECT  *
    ,   ROW_NUMBER() OVER (PARTITION BY Id ORDER BY BeginMile) RowNum
    FROM    @Runners
)

SELECT  a.Id [User]
,   a.BeginMile PrevBeginMile
,   a.EndMile PrevEndMile
,   b.BeginMile AfterBeginMile
,   b.EndMile AfterEndMile
,   b.BeginMile - a.EndMile Gap
FROM    OrderedUsers a
JOIN    OrderedUsers b
ON  a.Id = b.Id
AND a.EndMile <> b.BeginMile
AND a.RowNum = b.RowNum - 1

Answer 2

除了使用RowNumber（）[如在其他答案中]，您可以使用...

SELECT
  [current].User,
  [current].BeginMile                   AS [PrevBeginMile],
  [current].EndMile                     AS [PrevEndMile],
  [next].BeginMile                      AS [AfterBeginMile],
  [next].EndMile                        AS [AfterEndMile],
  [next].BeginMile - [current].EndMile  AS [Gap]
FROM
  myTable AS [current]
CROSS APPLY
  (SELECT TOP 1 * FROM myTable WHERE user = [current].User AND BeginMile > [current].BeginMile ORDER BY BeginMile ASC) AS [next]
WHERE
 [current].EndMile <> [next].BeginMile

或者可能......

FROM
  myTable AS [current]
INNER JOIN
  myTable AS [next]
    ON  [next].BeginMile != [current].EndMile
    AND [next].BeginMile  = (
                             SELECT
                               MIN(BeginMile)
                             FROM
                               myTable
                             WHERE
                               user = [current].User
                               AND BeginMile > [current].BeginMile
                            )

Answer 3

怎么样

WITH acte(user,beginmile,endmile) AS
(
SELECT user,start,end
ROW_NUMBER() OVER(PARTITION BY user ORDER BY START ASC) rownum
FROM mytable
)
SELECT base.user,base.beginmile,base.endmile,base.BeginMile - lead.EndMile Gap 
FROM acte base 
LEFT JOIN acte lead on base.id=lead.id AND base.rownum=lead.rownum-1
WHERE base.BeginMile - lead.EndMile > 0

查找不连续的用户记录

3 个答案: