Q114961: RFX_Date() function for TIMESTAMP_STRUCT

Article: Q114961
Product(s): Microsoft C Compiler
Version(s): 1.5,1.51,1.52,2.0,2.1,4.0
Operating System(s): 
Keyword(s): kbfile kbSample kbYear2000 kbDatabase kbMFC kbODBC kbVC
Last Modified: 11-FEB-2002

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++ for Windows, 16-bit edition, versions 1.5, 1.51, 1.52 
   - Microsoft Visual C++, 32-bit Editions, versions 2.0, 2.1, 4.0 
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SUMMARY
=======

The RFX_Date() record field exchange function transfers data from a date/time
field to a CTime object. AppWizard/ClassWizard will use this RFX_Date() function
when mapping date/time fields to variables.

The CTime object doesn't allow dates before the year 1970 and after the year 2037
(the CRT stores the time as a signed long, so the limit is actually Jan 18, 2038
19:14:07). Therefore, it may be better to use a TIMESTAMP_STRUCT (defined in the
SQLEXT.H) to retrieve the date/time information.

The structure TIMESTAMP_STRUCT is defined as:

  typedef struct tagTIMESTAMP_STRUCT
      {
          SWORD year;
          UWORD month;
          UWORD day;
          UWORD hour;
          UWORD minute;
          UWORD second;
          UDWORD fraction;
      } TIMESTAMP_STRUCT;

NOTE: The code in the following sample is not needed if you are using MFC version
3.1 or above (i.e. VC++ 2.1 or greater). MFC version 3.1 and above includes an
overloaded RFX_Date function that takes a TIMESTAMP_STRUCT. In this case, simply
changing the declaration of the recordset members to TIMESTAMP_STRUCT and
modifying any initializations of those members is sufficient.

The RFXDTE sample contains two files; RFXDATE.H and RFXDATE.CPP. These define a
RFX_Date() function which accepts a TIMESTAMP_STRUCT reference. To use the
function, you need to include the .CPP file into your project. If your project
doesn't use the standard precompiled header STDAFX.H then you may need to add
header files to the top of the .CPP file. Either in your precompiled header or
the RFXDATE.CPP file, you must include AFXWIN.H, AFXEXT.H, and AFXDB.H.

MORE INFORMATION
================

The following files are available for download from the Microsoft Download
Center:

Rfxdte.exe

For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:

  Q119591 How to Obtain Microsoft Support Files from Online Services

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Record field exchange (RFX) functions are called in the DoFieldExchange()
function of a CRecordset. RFX functions handle the transfer of data from a field
of a resultset (table that results from an SQL query) and the data members of a
CRecordset object.

To use the RFX_Date function in the RFXDTE sample, first define a
TIMESTAMP_STRUCT member of a CRecordset class. Then, pass the variable as the
third parameter to the RFX routine. The prototype for the function is:

  void RFX_Date(CFieldExchange* pFX, const char *szName,
      TIMESTAMP_STRUCT& value);

Be sure to include RFXDATE.H in the source file that calls RFX_Date().

Additional query words:

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Keywords          : kbfile kbSample kbYear2000 kbDatabase kbMFC kbODBC kbVC 
Technology        : kbAudDeveloper kbMFC
Version           : :1.5,1.51,1.52,2.0,2.1,4.0

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