Re: [Q] Update from a table - Mailing list pgsql-general

From Ladislav Lenart
Subject Re: [Q] Update from a table
Date
Msg-id 52A08E1C.1010702@volny.cz
Whole thread Raw
In response to Re: [Q] Update from a table  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
On 5.12.2013 15:14, Tom Lane wrote:
> Ladislav Lenart <lenartlad@volny.cz> writes:
>> What happens if I issue UPDATE SET FROM... but with incomplete/buggy WHERE
>> condition and thus SEVERAL rows from the from_list match ONE row to update?
>
> Any given row will be updated at most once.  However, the from_list row
> it gets updated against will be unpredictable, depending on the
> implementation of the join.
>
>             regards, tom lane

Makes perfect sense.

Thank you,

Ladislav Lenart



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