Re: Comparing dates in DDL - Mailing list pgsql-general

From David G. Johnston
Subject Re: Comparing dates in DDL
Date
Msg-id CAKFQuwbBQzEhUqQHm0zYPJ3aXbRYWO3pb=2k9_qM_O_C8EajkA@mail.gmail.com
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In response to Re: Comparing dates in DDL  (Rich Shepard <rshepard@appl-ecosys.com>)
Responses Re: Comparing dates in DDL  (Rich Shepard <rshepard@appl-ecosys.com>)
List pgsql-general
On Friday, January 4, 2019, Rich Shepard <rshepard@appl-ecosys.com> wrote:
On Fri, 4 Jan 2019, David G. Johnston wrote:

The is null expression is redundant since check constraints pass when the
result is unknown.

David,

  I wondered about this since NULL can be missing, unknown, or otherwise
defined. Are there benefits to allowing an empty value in that column when
checking that it's later than the start date rather than explicitly setting
a default date after the start date?


I don’t understand the question...

David J. 

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