Checking for null date

[Steve Albin]

On Sunday, March 29, 2009 sunshine at public.kherson.ua (Ruslan Zasukhin) wrote:

>> I'm using V4RB 4 and I need to know how to tell if a date field in a cursor is
>> null.  
>> 
>> I tried this:
>> 
>>   if VDateTime(cursor.Field(27)).Value <> nil then
>>     Return  VDateTime(cursor.Field(27)).Value
>>   else
>>     Return nil
>>   end
>>  
>> This returns a date field, but an invalid date which I would expect since I
>> know the field is <NULL>.
>> 
>> I tried this:
>> 
>>   if  self.cursor.Field(27).GetString <> "" then
>>     Return  VDateTime(cursor.Field(27)).Value
>>   else
>>     Return nil
>>   end
>>     
>> This returns nil as expected.
>> 
>> I can easily change my code to check the string value, but it seems that the
>> first way should work.  What am I doing wrong?
>
>Much more easy
>
>    if curs.Field(27).IsNull

That is easier.  Thanks!

But, the question was why doesn't VDateTime(cursor.Field(27)).Value return nil.  Is is becasue casting the date causes a date field to be created with unpredictable results?  This is probably an RB question more than a Valentina question...

Steve

-- 
Steve Albin - Montclair, NJ
http://www.jazzdiscography.com/
http://www.steve-albin.com/