SQL SERVER 如何查询两条记录之间的时间间隔？

create table #t (id int identity(1,1),dt varchar(20))
insert into #t values('2009-10-10 11:15:00')
insert into #t values('2009-10-10 11:17:00')
insert into #t values('2009-10-10 11:20:00')
insert into #t values('2009-10-10 11:24:00')
insert into #t values('2009-10-10 11:29:00')
insert into #t values('2009-10-10 11:36:00')
go

select * from #t

--1 2009-10-10 11:15:00
--2 2009-10-10 11:17:00
--3 2009-10-10 11:20:00
--4 2009-10-10 11:24:00
--5 2009-10-10 11:29:00
--6 2009-10-10 11:36:00

如何查询下一条记录与上一条记录的时间间隔
--ID    DT                  间隔
--1 2009-10-10 11:15:00 
--2 2009-10-10 11:17:00  2
--3 2009-10-10 11:20:00  3
--4 2009-10-10 11:24:00  4
--5 2009-10-10 11:29:00  5
--6 2009-10-10 11:36:00  7

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做个循环，用datediff比较。

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SQL code:
create table #t (id int identity(1,1),dt varchar(20))
insert into #t values('2009-10-10 11:15:00')
insert into #t values('2009-10-10 11:17:00')
insert into #t values('2009-10-10 11:20:00')
insert into #t values('2009-10-10 11:24:00')
insert into #t values('2009-10-10 1