SqlDataReader and 'invalid data attempt when no data present' error

[dkim18]

hi!

I am trying to excute sql command and get result.
The following code gives me an error, 'invalid data attempt when no data present'
The result that I am looking for is integer. Do I need to use something other than SqlDataReader?

Thanks in advance

----------------------------------------------------------
Try

objConn.Open()

Dim objCmd As SqlCommand = objConn.CreateCommand()

objCmd.CommandText = _
"SELECT max(SessionNum) FROM TreadMills WHERE UserID = '" & ID & "'"
Dim dataReader As SqlDataReader = objCmd.ExecuteReader()
MessageBox.Show("dataReader is " & dataReader.GetInt32(0))<-----------------error
Catch ex As Exception
MessageBox.Show("Error msg " & ex.Message)
-------------------------------------------------------

 

[MarkSweetland]

You could use the isNull() function to return a zero to ensure at least one record is returned when no sessionNum records exist in TreadMills for the specified UserID.

(I also like to specify a column name for aggregate columns...)

"SELECT [green]isNull([/green]max(SessionNum)[green],0) as MaxSessionNum[/green] FROM TreadMills WHERE UserID = '" & ID & "'"



Mark

&quot;You guys pair up in groups of three, then line up in a circle.&quot;
- Bill Peterson, a Florida State football coach

 

[dkim18]

Thank you for your info, but I am still having same err msg. My question was how to get integer result from excuting sql command.