Wow, I had never actually faced this problem (yet) but I spied it as a
possible stumbling block for porting MySQL apps, for which the standard
practice is inserting a NULL. As I have made a fairly thorough reading
of the docs (but may have not cross-correlated every piece of data yet,
obviously), I was surprised to find I hadn't figured this out myself.
It /seems/ obvious in retrospect, but it really baked my noodle when I
first looked at some ugly MySQL queries.
Respectfully, then, I move that a sentence outlining this functionality
be added to User Manual section 5.1.4, "The Serial Types."
Furthermore, anyone who has written or is writing a MySQL porting guide
should include this, if he hasn't.
Best,
Randall
On Thursday, June 26, 2003, at 08:49 AM, Bruno Wolff III wrote:
> On Thu, Jun 26, 2003 at 14:31:34 +0200,
> Dani Oderbolz <oderbolz@ecologic.de> wrote:
>>
>> It was written for MySQL, which can take NULL and then assign an
>> auto_increment.
>> However, in PostgreSQL I am getting problems, because it would not let
>> me insert NULL
>> into a NOT NULL column (which is perfectly sensible from my point of
>> view).
>> But as the author has also left out the column list in the insert, its
>> really tedious to change
>> the code.
>
> You can use the keyword DEFAULT instead of NULL and it will do what you
> want.
>
>> This way, there would be no possibility to circumvent the Value which
>> comes from the Sequence.
>
> You can use a unique constraint to enforce uniqueness.
>
>> Is there a way to change SERIAL this way?
>
> Well you can certainly write your own trigger to do this.
>
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