如何在SQL中获得第一列的输入结束？

Question

我有这样的表：

Sequence
2089697
2089738
2089838
2090368
2090400

我想要另一个专栏

Sequence; EndSequence  
2089697; 2089737
2089738; 2089837
2089838; 2090367
2090368; 2090399
2090400; null

EndSequence将是Sequence列的下一条记录的结尾。

Answer 1

FOR SQL SERVER 2005/2008

WITH records
AS
(
  SELECT  Sequence,
          ROW_NUMBER() OVER (ORDER BY Sequence ASC) rn
  FROM    TableName
)
SELECT  a.Sequence, b.Sequence - 1 EndSequence
FROM    records a
        LEFT JOIN records b
          ON a.rn+1 = b.rn

• SQLFiddle Demo

FOR SQL SERVER 2012

SELECT  SEQUENCE,
        LEAD(SEQUENCE) OVER (ORDER BY SEQUENCE) - 1 EndSequence
FROM    TableName

• SQLFiddle Demo

Answer 2

您可以将表连接到自身，其中连接中的条件是匹配右侧的记录大于左侧记录的值。然后按左侧的值进行分组，并聚合右侧的最小值：

SELECT l.Sequence, MIN(r.Seqence)-1 "EndSequence"
FROM table l
LEFT JOIN table r ON r.Sequence > l.Sequence
GROUP BY l.Sequence