Re: Comparing dates in DDL

Rob Sargent <robjsargent@xxxxxxxxx> · Fri, 4 Jan 2019 10:53:43 -0700

On 1/4/19 10:26 AM, Rich Shepard wrote:
On Fri, 4 Jan 2019, Rob Sargent wrote:

Is the end_date always knowable at record insert?

Rob,

  Not always. Sometimes projects have known end dates, other times the 
end
is interminate until it happens.

CHECK(end_date is null or start_date <= end_date)

  So a default of NULL should be applied, or just allowed to happen?

Thanks,

Rich

This is exactly what null is for.  Much preferable to some arbitrary 
value which will confuse analyses.