About Stephen Jackson Expertise I can help with questions regarding VB.NET syntax and object references, with data interfaces and with the design and creation of robust, data aware object classes. I can also be very helpful with creating distributable applications and provide tricks and tips on .msi creation. I also have extensive experience in designing SQL Server Databases and interfacing them with VB.NET. I try to avoid web specific questions, as that is an area of expertise all its own.
Experience
Experience in the Area: I have been a programmer in Visual Basic since version 1.0 and have worked with VB.NET (which is infinitely more powerful than previous versions) since its initial release and SQL Server, both as a corporate IT professional and professional consultant. I first wrote Basic in 1976 on a TRS 80 and have worked in Visual Basic 1.0 and every subsequent release of Microsoft Visual Basic. I worked for over 7 years as a Senior Level Consultant in the area and currently hold a Project Manager position in IT.
Education and Credentials: MBA in Econometrics, 1983, University of Memphis.
BBA in Financial Management, 1982, Fogelman College of Business and Economics, University of Memphis. Microsoft Certified Professional
Areas of Special Expertise:
My specialty is the design of Object Oriented Solutions with robust, data aware object classes. I generally avoid the classic ‘Three Tier’ model as I find it redundant and cumbersome to maintain. I also specialize in the creation of ‘User Friendly’ User Interfaces which help lessen the need for user training and help prevent user error. I work best with Windows Forms based applications, and while I do work in C# as well, I prefer to limit my questions here to Windows Forms based applications created in Visual Basic.NET and SQL Server. I wil also address questions relating to the distribution and installation of Windows Forms based applications created in VB.NET.
Expert: Stephen Jackson Date: 6/2/2008 Subject: Data Reader bug
Question Hi Stephen how are you? Concerning the code that i have sent to you, well you helped me a lot but there is still a little thing also. I wonder if you can help me with this task:
In the debug i get when i click a checkbox for the Private Sub loadskillset , the syntax highlighted "while (skillsetReader.read())": invalid attempt to call read when reader is closed Besides, when i click a second checkbox, i get in the Private sub appGrpchk_checkedChanged, the syntax highlighted: Adapt.Fill(ds,"AppGrpObj"), the following error: There is already an open DataReader associated with this command which must be closed first. Can you help me with this please?
Answer Carolina,
First, I apologize for taking so long! My (FIOS) Internet router went down this week and I just got a new one this afternoon!
OK, what you are seeing there is a call to a valid but closed datareader. I suspect this is a matter of order in which various objects are 'clicked' and so in the order in which your code is called. I would recommend the following ....
Go ahead and declare your DataReader objects at the top (general declarations). Then for each handler (action taken when a form object is clicked, button pressed, etc.) Set the DataReader then, let your code use it, and then close it so that another piece of code does not generate an error trying to open it again. This way you will always have a 'fresh' data reader and should not see errors. I know it is more code, but this kind of form code can be very ticklish ... almost as much as me! ;c)
