From: Richard Broersma Jr <rabroersma@yahoo.com>
To: Jon Collette <jon@etelos.com>
To: pgsql-sql@postgresql.org
Subject: Re: Boolean without default declared
Date: Wed, 15 Aug 2007 12:23:58 -0700 (PDT)
Message-ID: <775216.56005.qm@web31807.mail.mud.yahoo.com> (raw)
In-Reply-To: <46C349EA.5050201@etelos.com>
--- Jon Collette <jon@etelos.com> wrote:
> If a column with a boolean datatype doesn't have a default value. What
> type of value is set if nothing is inserted into that column? Here is
> my test table and the queries I have tried. I can't seem to be able to
> select the rows where happy has no value.
>
> *select * from users where happy = '';*
> ERROR: invalid input syntax for type boolean: ""
Databases have three value logic in it expressions.
is the expression true,
is the expression false,
is the expreassion unknown i.e. null.
SELECT * FROM users WHERE happy IS NULL;
UPDATE users SET happy = false WHERE happy IS NULL;
ALTER TABLE USER ALTER COLUMN happy SET NOT NULL;
Regards,
Richard Broersma Jr.
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To: pgsql-sql@postgresql.org
Cc: rabroersma@yahoo.com, jon@etelos.com
Subject: Re: Boolean without default declared
In-Reply-To: <775216.56005.qm@web31807.mail.mud.yahoo.com>
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