Null dates in Crystal Reports

To make this simple, I have a report with 3 columns. They are start date, end date and a formula field to subtract the start date from the end date to produce the number of days from start to end. This works fine except that there are conditions where the end date has no value and the database returns the date of 12/31/9999. I would like to create a formula that:

Checks for the null date and if it exists, does not perform a calculation but displays something identifying the null value and if the date is valid, perform the date subtraction (end_date - start_date).

I was using something like:

If IsNull (end_date) do something
(end_date - start_date)

Problem is I keep getting an error that Crystal wants a date in the last part of the formula.

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Hi alank2,
THe outcomes of an if statement must be the same datatype.
So you could do something like:

If IsNull (end_date)
end_date - start_date

Then you could suppress the formula field in the report if the result is 9999


You didn't explain what "do something" was but if you prefer a text output then you can do this:

If IsNull (end_date)
  'Invalid Date'
  CStr(end_date - start_date)


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