Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

COM in Win32

Posted on 2000-04-25
3
Medium Priority
?
303 Views
Last Modified: 2013-12-03
Im asked to write a program which will utilize MS databases.  I can write in any language I want.  I was going to use VB only because it allows access to COM objects such as ADO & DAO a lot easier than C.  But Im more familiar with using Win32 C calls and I like its efficency more, so Id like to try my hand at it in Win32.

Im not unfamiliar with COM (played with DirectX) but I haven't used it extensively.  Im wondering how I would access the DAO and/or ADO objects from within a Win32 app.  How would I find out the CLSID for it?  And how would I use CoCreateInstance() to load the components?

Thanks,
-Dan    
0
Comment
Question by:dmaroff
  • 2
3 Comments
 
LVL 23

Accepted Solution

by:
chensu earned 225 total points
ID: 2748441
First of all, you should use ADO instead of DAO for new applications. DAO is obselete.

Using ADO in C++ with #import can be as easy as in VB. Look into the ADO documentation. There are samples and tutorials.

Microsoft ActiveX Data Objects (ADO)
http://msdn.microsoft.com/isapi/msdnlib.idc?theURL=/library/psdk/dasdk/ados4piv.htm
0
 

Author Comment

by:dmaroff
ID: 2748688
It seems do-able but for some reason, I cant seem to open a recordset using a query:

-------------------------------------
dbPtr->Open("SELECT CITY FROM INFO_FCI WHERE ZIP = 10987", _variant_t((IDispatch *)pConnection,true), adOpenKeyset, adLockOptimistic, NULL);
------------------------------------
City is a attribute and so is zip.  But yet I get a "datatype mismatch error".
It seems that ADO in C is little different in VB.  Can you shoe me a few different SQL statement examples using this function.

Also, is there a seperate query function thats part of the _recordset object where I can requery the database, or do I just have to create another recordset?

Thanks,
-Dan
0
 
LVL 23

Expert Comment

by:chensu
ID: 2749189
>But yet I get a "datatype mismatch error".

I have no idea.

>Also, is there a seperate query function thats part of the _recordset object where I can requery the database, or do I just have to create another recordset?

You may use the Requery method or use the Close and Open methods.
0

Featured Post

Vote for the Most Valuable Expert

It’s time to recognize experts that go above and beyond with helpful solutions and engagement on site. Choose from the top experts in the Hall of Fame or on the right rail of your favorite topic page. Look for the blue “Nominate” button on their profile to vote.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article, I will show how to use the Ribbon IDs Tool Window to assign the built-in Office icons to a ribbon button.  This tool will help us to find the OfficeImageId that corresponds to our desired built-in Office icon. The tool is part of…
What my article will show is if you ever had to do processing to a listbox without being able to just select all the items in it. My software Visual Studio 2008 crystal report v11 My issue was I wanted to add crystal report to a form and show…
The purpose of this video is to demonstrate how to set up the WordPress backend so that each page automatically generates a Mailchimp signup form in the sidebar. This will be demonstrated using a Windows 8 PC. Tools Used are Photoshop, Awesome…
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…

971 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question