Re: Atomicity?

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Naz Gassiep wrote:
> I am getting an error that I think I understand, but that I didn't think
> should happen.
>
> Below is the output from psql that I am getting to trigger this error.
> If the violation of the constraint really is being caused WITHIN the
> query, doesn't that violate the principle of atomicity? I.e., operations
> and entities should be considered a single entire construct rather than
> a collection of smaller, discrete parts. Or do I have my understanding
> all wrong?
>
> In any case, how do I get around this problem?
>
> conwatch=# UPDATE replies SET rgt = rgt + 2 WHERE postid = 18 AND rgt >=
> 11;

Another work-around would be a loop.

Pseudo-code:
BEGIN
FOR :X IN
SELECT RGT, REPLYID
FROM REPLIES
WHERE POSTID = 18
AND RGT >= 11
DO
UPDATE REPLIES
SET RGT = RGT + 2
WHERE REPLIYID = :X.REPLYID;
END FOR;
END;

- --
Ron Johnson, Jr.
Jefferson LA USA

Is "common sense" really valid?
For example, it is "common sense" to white-power racists that
whites are superior to blacks, and that those with brown skins
are mud people.
However, that "common sense" is obviously wrong.
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