How an MFC Application Can Use the Visual FoxPro ODBC Driver

• Microsoft Visual FoxPro ODBC Driver version 1.0

SUMMARY

The Microsoft Foundation Classes can be used to create a application that allows access to data using ODBC drivers. The MFC AppWizard can create a basic framework that can be used to gain access to data with the Visual FoxPro ODBC driver.

This article gives the basic instructions for creating a simple MFC application by using the MFC AppWizard. For more specifics on MFC or the MFC Appwizard, refer to the Microsoft Visual C++ manuals and online books that are included with MFC 4.0. This example was created using Visual C++ 4.0.

MORE INFORMATION

Use the MFC AppWizard to create a basic framework:

1. Create a data source for Tastrade.dbc (in the Visual FoxPro Samples\Mainsamp\Data directory) and call it tastrade. Then open the customer database in Visual FoxPro, and modify the structure to allow NULL in all the fields. The MFC classes do not seem to distinguish between NULL and a blank value. When the Next button is clicked, the MFC class libraries send an update back to the table. If the field is blank, then a NULL is sent instead of spaces. When a NULL value is sent instead of spaces, an error occurs because the field does not allow NULLs.

2. Start Microsoft Developer Studio.

3. Select New from the File menu. Then select Project Work Space, and click the OK button. For the Project Type, select MFC AppWizard (exe). For the name, type test. Also, you may want to change the directory in which you save the project by clicking the Browse button and selecting a directory. Click the Create button.

4. In MFC AppWizard Step 1, select the Single document option, and then select English [United States] (APPWZENU.DLL). Click the Next button.

5. In MFC AppWizard Step 2, select the "Database view without file support" option. Click the Data Source button. Select the ODBC option, and then select tastrade (the name of the ODBC data source created in Step 1). Select the Snapshot option for the Recordset type, and click OK. Select the customer table, and click OK. Click the Next button.

6. In MFC AppWizard Step 3, select the None option for the OLE compound document support. Click the Next button.

7. In MFC AppWizard Step 4, clear the "Printing and print preview" check box. The Docking toolbar, Initial status bar, and 3D controls should be checked. Click the Next button.

8. In MFC AppWizard Step 5, for generate source file comments, select the "Yes, please" option and the "As a shared DLL" option for the the MFC library to use. Click the Next button.

9. In MFC AppWizard Step 6, Click the Finish button. Click the OK button.

1. Select the ResourceView tab. In the Outline, expand the Dialog and

       double-click IDD_TEST_FORM.
   

2. Click the Edit Box control, and draw an edit box on the form. From the

       View menu, choose ClassWizard. Click the Member Variables tab. Make
       sure the IDC_EDIT1 is the highlighted control, and click the Add
       Variable button. In the Member variable name list, select an
       m_company_name and leave Category as Value and Variable type as
       Cstring. Click the OK button.
   

3. From the Build menu, choose Build test.exe.

4. From the Build menu, choose Execute test.exe

REFERENCES

Inside Visual C++, Chapter 28 Inside ODBC, Chapter 8