Datareader无法正常工作 [英] Datareader not working
问题描述
您好我在使用datareader时遇到异常是代码
Me.SqlConnection1.Open（）
Me.SqlReservationCheck.Parameters（ " @ Ref"）。值= Ref
Dim Reader As SqlClient.SqlDataReader = _
Me.SqlReservationCheck.ExecuteReader（）
Dim我作为整数（）
Dim Index As Integer = 0
如果Reader.HasRows那么
而Reader.Read（）
ReDim Preserve I（指数）
我（指数）= Reader.Item（0）
指数+ = 1
结束虽然
结束如果
Reader.Close（）
Me.SqlConnection1.Close（）
当我执行While Reader.Read（）命令时，读者给出错误
但是如果Reader.HasRows然后返回true，有人可以帮我这个
-
后来
Scott Richards
Hi I am getting a exception while using a datareader here is the code
Me.SqlConnection1.Open()
Me.SqlReservationCheck.Parameters("@Ref").Value = Ref
Dim Reader As SqlClient.SqlDataReader = _
Me.SqlReservationCheck.ExecuteReader()
Dim I As Integer()
Dim Index As Integer = 0
If Reader.HasRows Then
While Reader.Read()
ReDim Preserve I(Index)
I(Index) = Reader.Item(0)
Index += 1
End While
End If
Reader.Close()
Me.SqlConnection1.Close()
When I execute the While Reader.Read() command the reader gives false
But the If Reader.HasRows Then returns true could someone help me with this
--
Later
Scott Richards
推荐答案
" Scott理查兹" <钪*********** @ discussions.microsoft.com>在消息中写道
news：38 ********************************** @ microsof t.com ...
"Scott Richards" <Sc***********@discussions.microsoft.com> wrote in message
news:38**********************************@microsof t.com...
嗨我在这里使用datareader时遇到异常是代码
Hi I am getting a exception while using a datareader here is the code
你得到了哪个例外，它会发生什么变化？
我真的不知道你希望有人能够帮助你给你
少量的您提供的信息。
John Saunders
Which exception do you get, and what line does it happen on?
I really don''t know how you expect anyone to be able to help you given the
small amount of information you''ve provided.
John Saunders
对于John的信息缺乏感到抱歉，当我写这篇文章时我花了5个小时来研究这个问题&很沮丧&累了。
问题是，当我运行datareader.read命令时，循环不会因为命令错误而导致错误
我已经通过运行datareader.read命令检查了它，而没有
while loop&信息在读者中，你建议我做什么？
从我所做的所有阅读中我发现没有像
这个。
感谢您的帮助
-
后来Scott Richards
John Saunders写道：
Sorry for the lack of information John, by the time I wrote this I had spent
5 hours researching the problem & was quite frustrated & tired.
The problem is that when I run the datareader.read command the loop does not
intiate because the command gives false
I have checked it by running the datareader.read command without without the
while loop & the information is in the reader, what do you suggest I do?
From all the reading on the subject I have done I have found nothing like
this.
Thank you for your help
--
Later Scott Richards
"John Saunders" wrote:
" Scott Richards" <钪*********** @ discussions.microsoft.com>在消息中写道
新闻：38 ********************************** @ microsof t.com。 ..
"Scott Richards" <Sc***********@discussions.microsoft.com> wrote in message
news:38**********************************@microsof t.com...
嗨我在使用datareader时遇到异常是代码
Hi I am getting a exception while using a datareader here is the code
你得到了哪个例外，它会发生什么行？
我真的不知道你希望有什么人能够帮助你提供你提供的少量信息。
John桑德斯
Which exception do you get, and what line does it happen on?
I really don''t know how you expect anyone to be able to help you given the
small amount of information you''ve provided.
John Saunders
" Scott Richards" <钪*********** @ discussions.microsoft.com>在留言中写道
新闻：E7 ********************************** @ microsof t.com ...
"Scott Richards" <Sc***********@discussions.microsoft.com> wrote in message
news:E7**********************************@microsof t.com...
抱歉缺少信息约翰，在我写这篇文章的时候我已经花了5个小时来研究这个问题&很沮丧&累了。
问题是，当我运行datareader.read命令时，循环确实没有启动，因为命令给出了错误
Sorry for the lack of information John, by the time I wrote this I had
spent
5 hours researching the problem & was quite frustrated & tired.
The problem is that when I run the datareader.read command the loop does
not
intiate because the command gives false
在这种情况下，我首先假设DataReader正常工作
。如果你从这个假设开始，你就会想知道为了使一个功能正常的DataReader能够立即返回false，你可能已经做了多少b $ b。例如，您确定您的查询是否正确？
是否正确？如果它需要参数，它们是否正确？例如，也许
你有一个带有尾随空格的字符串参数。
John Saunders
In a case like this, I would first assume that the DataReader is working
correctly. If you start with that assumption, you''re left to wonder what you
could possibly have done to make a correctly-functioning DataReader to
return false right away. For instance, are you certain that your query is
correct? If it requires parameters, are they correct? For instance, maybe
you''ve got a string parameter which has trailing spaces.
John Saunders
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