This article was contributed by Tom Archer.
Environment: Source will work on VC++ 5 and higher. However, the demo application will only
work on VC++ 6 and higher as it uses the CHtmlView class.
(continued)
This class (CAccessReports) was created for those of us who have the misfortune of
having to 1) use the MS Access database engine and 2) use the MS Access database engine from a
Visual C++ application. The CAccessReports class uses the Access Automation objects
to open a specified database, run a report (within Access), print the report and save the Access
database in HTML format so that it
can be viewed in a Visual C++ application. You can accomplish each of these tasks with a single
line of code. Here are some examples of how to use the CAccessReports class.
Examples of how to use the CAccessReports class
When you download the source code for the CAccessReports, you will also find a
full-fledged test application. However, it's always nice to be able to see what you're getting
before you invest the time in downloading, unzipping and running someone else's code. Therefore,
here are some code snippets that show how easy the
CAccessReports class is to use.
Instantiating a CAccessReports object
How you choose to instantiate CAccessReports object depends
on how you plan to use it in your application. The first argument of the
CAccessReports is the fully qualified name of the database file.
The second argument specifies whether you want the CAccessReports
class to preload all of the report names. An example of when you would want
the class to retrieve all of the report names is if your application needs to
display a list of the reports to the end-user. Otherwise, if you are instantiating
a CAccessReports object in order to run, print or display specific reports whose
names are known at compile-time, you can pass a value of FALSE for this
argument.
CAccessReports accessReports(YOUR_ACCESS_DATABASE, TRUE);
CAccessReports accessReports(YOUR_ACCESS_DATABASE, FALSE);
Getting a List of Reports from an Access Database
If you specified a value of TRUE for the second argument of the
CAcessReport constructor, you can then retrieve the list of reports
for a given Access database. Here's an example of a simple loop to retrieve
and display all of the report names.
CAccessReports accessReports(YOUR_ACCESS_DATABASE, TRUE);
for (int i = 0; i < accessReports.m_reports.GetSize(); i++)
{
AfxMessageBox(accessReports.m_reports[i]);
}
Running an Access Report
While the CAccessReports class does allow you to display an Access report
from a Visual C++ application (shown below), there are still valid reasons to run the
report from within Access. Therefore, the RunReport member function does exactly
that.
CAccessReports accessReports(YOUR_ACCESS_DATABASE, FALSE);
accessReports.RunReport(YOUR_REPORT_NAME);
Printing an Access Report
The PrintReport function takes as its only argument the name of a report to print.
This function calls RunReport and then uses Automation to print the report.
CAccessReports accessReports(YOUR_ACCESS_DATABASE, FALSE);
accessReports.PrintReport(YOUR_REPORT_NAME);
Displaying an Access Report (Visual C++ 6.0)
Access Automation doesn't allow for the ability to redirect the output of a report to a
given window. However, it does allow for a report to be run and then saved in HTML format. That
combined with the new Visual C++ 6.0 CHtmlView gives you the ability to run an
Access report and display it in a Visual C++ application. In the example below,
CAccessReportView is a CHtmlView derived class.
void CAccessReportView::OnInitialUpdate()
{
CHtmlView::OnInitialUpdate();
CAccessReports accessReports(YOUR_ACCESS_DATABASE, FALSE);
accessReports.SaveAsHtml(YOUR_REPORT_NAME, DESTINATION_FOLDER);
Navigate2(FULLY_QUALIFIED_FILE_NAME, NULL, NULL);
}
Displaying an Access Report (Visual C++ 5.0)
Unfortunately, Visual C++ 5.0 does not have the CHtmlView class.
However, you can still display Access reports using the WebBrowser
control (in the Visual C++ Component Gallery). In order to display the Access
report in a Visual C++ 5 application, simply instantiate a
CAccessReports object, call its SaveAsHtml
member function and then call the WebBrowser control's
Navigate function specifying the name of the HTML file.
- 1. Access Automation can not be used to get the entire list of
reports for a an Access database. Therefore, if you
specify
TRUE to the second argument of the
CAccessReports constructor, the class attempts to use
the MFC DAO classes to access the msysobjects table of the specified
database. In order to accomplish this, you must
give the Admin
user "read" priveleges to the database's msysobjects table.
If your application is printing or viewing
a specific report from a specific database and you don't need the list of
reports, then this limitation does not apply. If anyone knows of a better
way of doing this, I'm always open to learning new things :)
Downloads
Download source - 38 KB
Download demo project - 60 KB
Date Last Updated: October 22, 2000
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About the Author
I am a Program Manager and Content Strategist for the Microsoft MSDN Online team managing the Windows Vista and Visual C++ developer centers.
Before being employed at Microsoft, I was awarded MVP status for the Visual C++ product. A 20+ year veteran of programming with various languages - C++, C, Assembler, RPG III/400, PL/I, etc. - I've also written many technical books (Inside C#, Extending MFC Applications with the .NET Framework, Visual C++.NET Bible, etc.) and 100+ online articles.
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