SAMPLE: RFX_Date() function for TIMESTAMP_STRUCT

WINDOWS        | WINDOWS NT

The information in this article applies to:

• The Microsoft Foundation Classes (MFC), included with:

      - Microsoft Visual C++ for Windows, versions 1.5, 1.51, and 1.52
      - Microsoft Visual C++ 32-bit Edition, versions 2.0, 2.1, and 4.0
  

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;

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.

Download RFXDTE.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:

• Microsoft Download Service (MSDL)

        Dial (206) 936-6735 to connect to MSDL
        Download RFXDTE.EXE (size: 17183 bytes) 
  

• Internet (anonymous FTP)

        ftp ftp.microsoft.com
        Change to the \softlib\mslfiles directory
        Get RFXDTE.EXE (size: 17183 bytes) 
  

MORE INFORMATION

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);