为什么这段执行后显示不出结果来？

[Zi_Yuan]

declare @theDate datetime,@evi_date datetime
set @theDate='2009-01-11'
while @theDate>@evi_date
begin
DECLARE evi_cursor CURSOR FOR
select evi_date from evidence
--打开游标
OPEN evi_cursor
--取出值
FETCH NEXT FROM evi_cursor INTO @evi_date
select @evi_date
--循环取出游标的值
WHILE @@FETCH_STATUS = 0
BEGIN
FETCH NEXT FROM evi_cursor
INTO @evi_date

end
CLOSE evi_cursor --关闭游标
DEALLOCATE evi_cursor --释放游标
end

[Zi_Yuan]

实际上是有记录的

[rucypli]

哪里有显示结果的代码

[-狙击手-]

declare @theDate datetime,@evi_date datetime
set @theDate='2009-01-11'
while @theDate>@evi_date
begin
DECLARE evi_cursor CURSOR FOR
select evi_date from evidence
--打开游标
OPEN evi_cursor
--取出值
FETCH NEXT FROM evi_cursor INTO @evi_date

--循环取出游标的值
WHILE @@FETCH_STATUS = 0
BEGIN
select @evi_date
FETCH NEXT FROM evi_cursor
INTO @evi_date

end
CLOSE evi_cursor --关闭游标
DEALLOCATE evi_cursor --释放游标
end

[Zi_Yuan]

消息里面总是出现“命令已成功完成。”，显示不出值

[moon&sean]

应该这样写:
declare @theDate datetime,@evi_date datetime
set @theDate='2009-01-11'
while @theDate>@evi_date
begin
DECLARE evi_cursor CURSOR FOR
select evi_date from evidence
--打开游标
OPEN evi_cursor
--取出值
FETCH NEXT FROM evi_cursor INTO @evi_date

--循环取出游标的值
WHILE @@FETCH_STATUS = 0
BEGIN
select @evi_date
FETCH NEXT FROM evi_cursor
INTO @evi_date

end
CLOSE evi_cursor --关闭游标
DEALLOCATE evi_cursor --释放游标
end

[you_tube]

declare @theDate datetime,@evi_date datetime
set @theDate='2009-01-11'
while @theDate>@evi_date
begin
DECLARE evi_cursor CURSOR FOR
select evi_date from evidence
--打开游标
OPEN evi_cursor
--取出值
FETCH NEXT FROM evi_cursor INTO @evi_date

--循环取出游标的值
WHILE @@FETCH_STATUS = 0
BEGIN
select @evi_date

FETCH NEXT FROM evi_cursor
INTO @evi_date

end
CLOSE evi_cursor --关闭游标
DEALLOCATE evi_cursor --释放游标
end

[Zi_Yuan]

if exists (select 1 from sysobjects
where id = object_id('evi_date') and type = 'U')
drop table evi_date
create table evi_date(evi_id int,evi_date datetime)
declare @theDate datetime,@evi_date datetime,@evi_id int
set @theDate='2009-01-12'
DECLARE evi_cursor CURSOR FOR
select evi_id,evi_date from evidence order by evi_date
--打开游标
OPEN evi_cursor
--取出值
FETCH NEXT FROM evi_cursor INTO @evi_id,@evi_date

--循环取出游标的值
WHILE @@FETCH_STATUS = 0
BEGIN
--print @evi_date
if(@theDate<@evi_date) break
insert into evi_date values(@evi_id,@evi_date)
FETCH NEXT FROM evi_cursor
INTO @evi_id,@evi_date
end
CLOSE evi_cursor --关闭游标
DEALLOCATE evi_cursor --释放游标

select * from evi_date

服务器: 消息 213，级别 16，状态 5，行 19
插入错误: 列名或所提供值的数目与表定义不匹配。

[contendskyline]

我个人认为不显示结果的原因可能是是：datetime类型的数据不能直接比较大小！

[Zi_Yuan]

if exists (select 1 from sysobjects
where id = object_id('evi_date') and type = 'U')
drop table evi_date
create table evi_date(evi_id int,evi_date datetime)
declare @theDate datetime,@evi_date datetime,@evi_id int
set @theDate='2009-01-12'
DECLARE evi_cursor CURSOR FOR
select evi_id,evi_date from evidence order by evi_date
--打开游标
OPEN evi_cursor
--取出值
FETCH NEXT FROM evi_cursor INTO @evi_id,@evi_date
print @evi_id
print @evi_date

--循环取出游标的值
WHILE @@FETCH_STATUS = 0
BEGIN
--print @evi_date

if(@theDate<@evi_date) break
insert into evi_date (evi_id,evi_date) values(@evi_id,@evi_date)
FETCH NEXT FROM evi_cursor
INTO @evi_id,@evi_date
end
CLOSE evi_cursor --关闭游标
DEALLOCATE evi_cursor --释放游标

select * from evi_date


这样就对了

[-狙击手-]

[Quote=引用 8 楼 contendskyline 的回复:]
我个人认为不显示结果的原因可能是是：datetime类型的数据不能直接比较大小！
[/Quote]

可以的