Re: Strange behavior of "=" as assignment operator

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От Pavel Stehule
Тема Re: Strange behavior of "=" as assignment operator
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Msg-id CAFj8pRAhWCokhiesrAD=QSwm=XiMzrMRpgsSn_g7=WuVS-dZEg@mail.gmail.com
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Ответ на Re: Strange behavior of "=" as assignment operator  (Stephen Frost <sfrost@snowman.net>)
Список pgsql-general
2013/5/28 Stephen Frost <sfrost@snowman.net>:
> * Moshe Jacobson (moshe@neadwerx.com) wrote:
>> It seems that the comparison operator "=" is functioning as the assignment
>> operator ":=" in this plpgsql trigger script I wrote. I was under the
>> impression that "=" is only for comparison and not assignment. If this is
>> true, please explain the transcript below. If it's not true, where is this
>> documented? I'm using PostgreSQL 9.1.4.
>
> Both are supported.  It's not really documented as using '=' is
> considered 'legacy' but it's also extensively used and removing it would
> break quite a bit of code for people.
>
> My general feeling is that we should either document it *as* legacy
> or add it to the "list-of-things-to-break-in-10.0". :)

should be cleaned and removed

same undocumented behave has GET DIAGNOSTICS STATEMENT, ":=" is
allowed there :-(

note from source code

assign_operator>: '='<->/* not documented because it might be removed someday */
<------><------><------><------>| COLON_EQUALS
<------><------><------><------>;

Regards

Pavel



>
>         Thanks,
>
>                 Stephen


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