Re: exception error when accessing SQL database

From: William \(Bill\) Vaughn (billvaRemoveThis_at_nwlink.com)
Date: 09/23/04 

Date: Thu, 23 Sep 2004 16:13:43 -0700

Each subroutine that executes code in VB.NET needs to have a Try/Catch/End
Try block to trap the exceptions. If you don't the system has to handle the
exceptions itself (which is what you're seeing).

Try
    Do something in code...

Catch Ex as Exception
    msgbox ex.tostring ' to show what REALLY happened
End try

ASP.NET is the programming form that's used to create browser-applications
run on IIS. It's different than Windows forms applications. 

-- 
____________________________________
William (Bill) Vaughn
Author, Mentor, Consultant
Microsoft MVP
www.betav.com
Please reply only to the newsgroup so that others can benefit.
This posting is provided "AS IS" with no warranties, and confers no rights.
__________________________________
"whitetulips" <whitetulips@discussions.microsoft.com> wrote in message 
news:0EBF92E0-4CD9-4A7A-A5F6-DB9F8E83B23E@microsoft.com...
> hi
>
> I am sorry, are you refering to this: The error output from the message
> window was "An unhandled exception of type
> 'System.Data.SqlClient.SqlException' occurred in 
> System.Data.SqlClient.dll"?
>
> by the way, what you mean by asp.net environment? (pardon me cos i m 
> really
> a newbie -_-")? From my understanding of asp, it's a transportation 
> language
> to send my sql queries to the server to retrieve the data. The asp codes,
> together with the sql codes, are placed within html codes. The data 
> extracted
> are then displayed in a web form. However, I am not displaying my data
> extracted from the database on a web form. The data are simply displayed 
> in a
> data grid(for eg.), within a window, which will appear in the screen of 
> the
> pda emulator. And I followed some sample codes in a "Teach yourself 
> ADO.NET"
> book to access the database. How will that be confused with asp.net?
>
> pardon me and thanks,
> lynn
>
>
> "Val Mazur" wrote:
>
>> You still did not post actual exception here. Do you run your code from
>> ASP.NET environment? If yes, then most likely you just do not have
>> permissions for ASPNET account to connect to the database. In a case if 
>> you
>> test it from the development environment it will work, because you do it
>> from the Windows environment for the local user
>>
>> -- 
>> Val Mazur
>> Microsoft MVP
>>
>>
>> "whitetulips" <whitetulips@discussions.microsoft.com> wrote in message
>> news:CF66A6AD-62ED-4F51-BDFE-8E7D3CEA624E@microsoft.com...
>> > hihi
>> >
>> >    It gave an unhandled exception. However, this operation should not 
>> > give
>> > an exception. That is why I did not write an a try n catch for an
>> > exception.
>> > I wonder if it's because I failed to connect to the database.
>> >    However, I did try to use the option "Tools"->"Connect to Database" 
>> > to
>> > test the connection between my visual studio .net and the database. It
>> > says
>> > "Test Connection Succeeded."
>> >    Also, I tried to change the (local) to the actual server name and 
>> > and
>> > it's still the same. ie. "SqlConnection cn = new
>> > SqlConnection(@"server=baby\NetSDK; DataBase=pubs;Integrated
>> > Security=SSPI");" , given that baby(for eg.) is the server name. I have
>> > also
>> > tried (baby), but to not avail. I even tried "BABY" which is the SQL
>> > server's
>> > name, though I know that's dumb and indeed it's of no help. -_-" cause 
>> > I
>> > am
>> > really desparate.. =(
>> >
>> >    By the way, what's the difference between the 2 statements in the
>> > following? What's the significance of the "@", the brackets in 
>> > "(local)"
>> > and
>> > "\NetSDK"? And what's the difference in the syntax "local" and
>> > "localhost"?
>> > 1) SqlConnection cn = new SqlConnection("Initial Catalog=pubs;Data
>> > Source=localhost;Integrated Security=SSPI;");
>> > 2) SqlConnection cn = new SqlConnection(@"server=(local)\NetSDK;
>> > DataBase=pubs;Integrated Security=SSPI");
>> >
>> >    Please help.
>> >
>> > thks.
>> > lynn
>> >
>> >
>> > "Val Mazur" wrote:
>> >
>> >> Hi,
>> >>
>> >> What kind of exception do you get? try to replace (local) with the 
>> >> actual
>> >> server name
>> >>
>> >> -- 
>> >> Val Mazur
>> >> Microsoft MVP
>> >>
>> >>
>> >> "whitetulips" <whitetulips@discussions.microsoft.com> wrote in message
>> >> news:2A6247C7-0C32-4D20-B9ED-21A7583E689E@microsoft.com...
>> >> > Dear all,
>> >> >    I am using visual studio .net and c# to develope mobile 
>> >> > applcations
>> >> > and
>> >> > I am new to both. I used the following code under the option "visual 
>> >> > c#
>> >> > project", "Smart device application". It was successfully built, but
>> >> > the
>> >> > execution got stuck with exception error when it hit the line /*dr =
>> >> > cmd.ExecuteReader(CommandBehavior.CloseConnection);*/.
>> >> >
>> >> > private void UseDataReader_Click(object sender, System.EventArgs e)
>> >> > {
>> >> > listBox1.Items.Clear();
>> >> > SqlConnection cn = new SqlConnection(@"server=(local)\NetSDK;
>> >> >                                  DataBase=pubs;Integrated
>> >> > Security=SSPI");
>> >> >
>> >> > SqlDataReader dr;
>> >> > SqlCommand cmd = new SqlCommand();
>> >> > cmd.CommandText = "Select au_lname, au_fname from Authors";
>> >> > cmd.Connection = cn;
>> >> > cn.Open();
>> >> > dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
>> >> > .......................
>> >> > }
>> >> >
>> >> > I had the similar problem before when I was working with the option
>> >> > "visual
>> >> > c# project", "Windows Application". But the execution was fine after 
>> >> > i
>> >> > changed the database connection statement to /*SqlConnection cn = 
>> >> > new
>> >> > SqlConnection("Initial Catalog=pubs;Data Source=localhost;Integrated
>> >> > Security=SSPI;");*/. However, this does not seem to solve the 
>> >> > problem
>> >> > here.
>> >> >
>> >> > Can anyone help?
>> >> >
>> >> > thks
>> >> > lynn
>> >>
>> >>
>> >>
>>
>>
>>

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