On 12/30/2016 08:51 AM, Rich Shepard wrote:
> On Fri, 30 Dec 2016, David G. Johnston wrote:
>
>> "The CHECK clause specifies an expression producing a Boolean result
>> which
>> new or updated rows must satisfy for an insert or update operation to
>> succeed. Expressions evaluating to TRUE or UNKNOWN succeed."
>>
>> NULL == "UNKNOWN"
>
> David,
>
> I forgot about that. Thanks for pointing it out to me.
What it comes down to is if you do not want NULL values in a column then
specify NOT NULL on the column.
>
> Regards,
>
> Rich
>
>
--
Adrian Klaver
adrian.klaver@aklaver.com