sqlclient.hasrows not functioning properly....or bad code?

[etjohnson81]

The code below is what I am using to determine if credentials were good.

Try
            While sqlOutput.Read

                If sqlOutput.HasRows = False Then
                    lblErrorMessage.Text = "You don't have access to this site.  Please contact your administrator."
                    lblErrorMessage.Visible = True
                End If

                If sqlOutput.HasRows = True Then
                    lblErrorMessage.Text = "Login Success"
                    lblErrorMessage.Visible = True

                    'Load user information

                End If
            End While
        Catch ex As Exception
            lblErrorMessage.Text = "An Error Occured During Login"
        End Try

When the table has records (hasrows = true)... The Login Success is shown.

When there are no records (hasrows = false)...Nothing is displayed.

I had this working previously with slightly different code that used a Count(*) in the SQL String, but I would like to run only one SQL read if possible.

Anyone know why this might not work?

Travis

http://www.bluelinenetworks.net

 

[jbenson001]

I assume you are using a datareader here. I think you need to check the .HasRows property before you .read.

Check some examples in VS Help.

 

[etjohnson81]

I get back the proper value from the datareader.hasrows, I did a test display of the output in a label field and it returns properly, but not when i output during the false portion of the if, only during the true piece

Travis

http://www.bluelinenetworks.net

 

[Craig0201]

If there are no records, it doesn't enter the loop ergo no values on false.

Elementary program control flow, my dear Watson.

A simple step through would have shown you this.

C

 

[jmeckley]

I had this working previously with slightly different code that used a Count(*) in the SQL String, but I would like to run only one SQL read if possible.

what's wrong with 2 sql queries? I doubt there is a noticable and/or quantifiable difference between the previous and proposed query plans.

I would also make the recommendation to exit the connection asap. load the reader into a datatable, close/dispose the connection and then run your logic/gui. according to the code above you never clean up after the connection. either use a finally block, or a using statement. both would do the same to.

Jason Meckley
Programmer
Specialty Bakers, Inc.

 

[etjohnson81]

DOAH! I missed that piece of out of order logic. Thanks guys

Travis

http://www.bluelinenetworks.net