Обсуждение: Query about Boolean Data Type

Hi

This may seem a bit simplistic but how do you match a select on a
boolean data column where the entry is false or null

Thanks

Richard

On Fri, Aug 08, 2003 at 10:29:37 +0100,
  Richard Hurst <richard.hurst@kirklees.gov.uk> wrote:
> Hi
>
> This may seem a bit simplistic but how do you match a select on a
> boolean data column where the entry is false or null

select * from table where columun is false or column is null;
or
select * from table where not column is true;

"Richard Hurst" <richard.hurst@kirklees.gov.uk> writes:
> This may seem a bit simplistic but how do you match a select on a
> boolean data column where the entry is false or null

Slick way:
        ... WHERE foo IS NOT TRUE;
Straightforward way:
        ... WHERE (NOT foo) OR (foo IS NULL);
or
        ... WHERE (foo = false) OR (foo IS NULL);
but not
        ... WHERE (foo = false) OR (foo = NULL);
The last will not do what you expect.

            regards, tom lane

--On Friday, August 08, 2003 10:29:37 +0100 Richard Hurst
<richard.hurst@kirklees.gov.uk> wrote:

> Hi
>
> This may seem a bit simplistic but how do you match a select on a
> boolean data column where the entry is false or null
select * from table where field='f' or field is null;

should do it.


>
> Thanks
>
> Richard
>
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