INFO: OLE Servers Return Date Calculation Results as Seconds

ID: Q185859

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a

SUMMARY

By default, a date data type passed in to or out of a Visual FoxPro OLE server is automatically converted to Datetime format. Because of this, the result of a date calculation is returned as seconds.

MORE INFORMATION

The Visual FoxPro OLE servers, by default, convert the Date data type to DateTime. If you try to subtract two datetime() variables, within an OLE server, the result is returned as seconds (n * 86400). You may use the TTOD() function if you need the number returned as days.

Steps to Reproduce Behavior

Using Visual FoxPro, build an OLE DLL using the following code and name it DateFunc:


      DEFINE CLASS DateFunc AS custom OLEPUBLIC

         Name = "DateFunc"

         PROCEDURE DifferDate
            PARAMETERS BDate, EDate
            x=EDate-BDate
            RETURN INT(x)
        ENDPROC

      ENDDEFINE

After building the OLE DLL, issue the following commands in the Command window:
```
      ox=CREATEOBJECT("DateFunc.DateFunc")
      ? ox.Differdate({01/01/98},{01/05/98}) 
```
Note that instead of returning four days, 345600 (4*86400) seconds is returned.

To return four days from the OLE DLL, replace the commands in the DifferDate procedure as shown below:


      PROCEDURE DifferDate
         PARAMETERS BDate, EDate
         x=ttod(EDate)-ttod(BDate)
         RETURN INT(x)
      ENDPROC

REFERENCES

For additional information, please see the following articles in the Microsoft Knowledge Base:

Q168053 HOWTO: Visual FoxPro Automation Servers and Active Server Pages

Q156014 How To Set Up OLE Automation in Visual FoxPro 5.0

Additional query words: kbDSupport kbdse VFP600REL kbole

Keywords :
Version : WINDOWS:5.0,5.0a
Platform : WINDOWS
Issue type : kbinfo