Re: 0/1 vs true/false

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Тема Re: 0/1 vs true/false
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Msg-id 00bb01c35127$e3a19de0$2766f30a@development.greatgulfhomes.com
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Ответ на Re: 0/1 vs true/false  (Franco Bruno Borghesi <franco@akyasociados.com.ar>)
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I doubt it, same way '0' and '1' have not disappeared despite 0 and 1 have.  There is still a function that can convert a string to a boolean.  There is no function to convert an integer to a boolean, which is why 0 and 1 do not work but '0', 'f', '1', 't' all work.
 

Terry Fielder
Manager Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
terry@greatgulfhomes.com
Fax: (416) 441-9085

 
-----Original Message-----
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Franco Bruno Borghesi
Sent: Wednesday, July 23, 2003 10:21 AM
To: Jochem van Dieten
Cc: Jean-Christian Imbeault; pgsql-general@postgresql.org
Subject: Re: [GENERAL] 0/1 vs true/false

This makes me wonder, what about 't' and 'f'?... will they disappear in newer versions of postgreSQL?

On Wed, 2003-07-23 at 09:21, Jochem van Dieten wrote:
Jean-Christian Imbeault wrote:
> Just having a small argument with an application developer ...
> 
> is using 0/1 for boolean types SQL compliant? I am trying to convince 
> him that the proper SQL compliant (and postgresql compliant) syntax is 
> true/false but he won't budge ...
> 
> The app as currently written no longer works with postgres because they 
> code uses 0/1 instead of the now enforced true/false for boolean types.
> 
> Can someone point me to an SQL spec and section where this is clearly 
> stated out?

Would this be what you are looking for:

ISO/IEC 9075-2:1999 (E) ©ISO/IEC
5.3 <literal>
(..)
<boolean literal> ::=    TRUE    | FALSE    | UNKNOWN


Additionally about UNKNOWN:

ISO/IEC 9075-2:1999 (E) ©ISO/IEC
4.6 Boolean types
The data type boolean comprises the distinct truth values true 
and false . Unless prohibited by a NOT NULL constraint, the 
boolean data type also supports the unknown truth value as the 
null value. This specification does not make a distinction 
between the null value of the boolean data type and the unknown 
truth value that is the result of an SQL <predicate>, <search 
condition>, or <boolean value expression>; they may be used 
interchangeably to mean exactly the same thing.

HTH,
Jochem




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