Re: Database problem.....HELP

Sorry, DM, I have never used the wizard, I've always created my own connections / commands and executed them myself. In general I've found the visually added DB objects and wizard-assisted setup creates code that is either inefficient and/or not a scalable and maintainable design, plus for me at least it's a poor way to learn how everything works.

I would suggest obtaining a valid connection string that works with this DB (verified in Access or some other interactive tool), then programmatically create and open a connection, create a command, add any needed parameters, etc. I would Google for something like "ADO.NET basic tutorial" for fundamental code examples. Then, create a console app whose sole purpose is to create and open a connection, create a command object, and then return a query result and display a couple of fields of the first 5 records. Do this with a DataReader and then with a DataAdapter so you get a feel for how both work. Trap all errors and step through your code with a debugger until you are satisfied that (a) you understand it and (b) it works correctly.

When you have accomplished this then you can work it into something more generally useful like a Winforms or ASP.NET app with some bound controls. Take it step by step.

In my opinion, for what it's worth, avoid the "drop a connection onto a form" approach. It is really only appropriate for the most trivial apps and does not provide you with deep understanding of what you're doing. Same goes for relying on CommandBuilders and the like, at least until you understand how to build commands yourself so you can understand the quirks and limitations of the hand-holding provided by generated commands.

Best,

--Bob


DM wrote: 
Sorry so short on info......novice at work.....

I am just learing csharp and was going through a tutorial from microsoft and learn visual studio.net .... there was no major code yet. Went to add a class then seleceted SQL Database then set the name to MyCompany.mdf and clicked add, then the Data Source Configuration Wizard window opens with this error. the first part of the window says "Which database objects do you want in your dataset?", the rest of the window has the error that I listed below. The only choice that i have at the bottom of the window is the Previous or Cancel button. I am sure that there is probably a whole procedure to setting up even a basic database, but I know they did not show it in any of the tutorials so far..... I have worked with other languages but never with csharp or c++ for that matter...

Thanks for the POST.
DM


"Bob Grommes" wrote:


Much more info would be needed to help you.

What database? OS version? DB version? Configuration info? Connection string? Is this happening when you connect, when you issue a query, or someplace else? Sample code would be really useful here.

All I can tell from the error is you are probably using the OleDb client library and something down in the basement plumbing has sprung a leak.

--Bob

DM wrote:

newbie trying to set up a Database and keep getting the same result. ERROR

An error occured while retrieving the information from the database:

Unable to cast COM object of type 'System._ComObject' to interface type
'Microsoft.VisualStudio.OLE.Interop.IServiceProvider'. This operation failed because the QueryInterface call on th COM component for the interface with IID '{65D5140C1-7436-11CE-8034-00aa006009FA}' failed with HRESULT: 0x80004002 (No such interface supported(Exception from HRESULT: 0x80004002 (E_NOINTERFACE))).

any help would be greatly appreciated.

Thanks DM 

.