Re: proposal: multiple psql option -c - Mailing list pgsql-hackers

From Tom Lane
Subject Re: proposal: multiple psql option -c
Date
Msg-id 22800.1447788325@sss.pgh.pa.us
Whole thread Raw
In response to Re: proposal: multiple psql option -c  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: proposal: multiple psql option -c  (Pavel Stehule <pavel.stehule@gmail.com>)
Re: proposal: multiple psql option -c  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Nov 16, 2015 at 6:05 PM, Andrew Dunstan <andrew@dunslane.net> wrote:
>> I honestly don't see what's so confusing about it, and if there is any
>> confusion then surely we could make sure what's happening is well
>> documented.

> +1.  I'm actually kind of wondering if we should just back up and
> change the way -c works instead, and allow it to be specified more
> than once.  The current behavior is essentially a crock that has only
> backward compatibility to recommend it, and not having two
> confusingly-similar options is of some non-trivial value.

Well, it's not *entirely* true that it has only backwards compatibility
to recommend it: without -c in its current form, there would be no way
to test multiple-commands-in-one-PQexec cases without hacking up some
custom test infrastructure.  That's not a very strong reason maybe, but
it's a reason.  And backwards compatibility is usually a strong argument
around here anyway.

I've not been following this thread in any detail, but have we considered
the approach of allowing multiple -c and saying that each -c is a separate
PQexec (or backslash command)?  So the semantics of one -c wouldn't change,
but commands submitted through multiple -c switches would behave
relatively unsurprisingly, and we wouldn't need two kinds of switch.

Another issue here is how -1 ought to interact with multiple -c.
        regards, tom lane



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