Re: psql: Add command to use extended query protocol

so 5. 11. 2022 v 7:35 odesílatel Corey Huinker <corey(dot)huinker(at)gmail(dot)com>
napsal:

> On Fri, Nov 4, 2022 at 11:45 AM Peter Eisentraut <
> peter(dot)eisentraut(at)enterprisedb(dot)com> wrote:
>
>> On 02.11.22 01:18, Corey Huinker wrote:
>> >
>> > SELECT $1, $2 \gp 'foo' 'bar'
>> >
>> >
>> > I think this is a great idea, but I foresee people wanting to send that
>> > output to a file or a pipe like \g allows. If we assume everything
>> after
>> > the \gp is a param, don't we paint ourselves into a corner?
>>
>> Any thoughts on how that syntax could be generalized?
>>
>
> A few:
>
> The most compact idea I can think of is to have \bind and \endbind (or
> more terse equivalents \bp and \ebp)
>
> SELECT * FROM foo WHERE type_id = $1 AND cost > $2 \bind 'param1' 'param2'
> \endbind $2 \g filename.csv
>
> Maybe the end-bind param isn't needed at all, we just insist that bind
> params be single quoted strings or numbers, so the next slash command ends
> the bind list.
>
> If that proves difficult, we might save bind params like registers
>
> something like this, positional:
>
> \bind 1 'param1'
> \bind 2 'param2'
> SELECT * FROM foo WHERE type_id = $1 AND cost > $2 \g filename.csv
> \unbind
>
> or all the binds on one line
>
> \bindmany 'param1' 'param2'
> SELECT * FROM foo WHERE type_id = $1 AND cost > $2 \g filename.csv
> \unbind
>
> Then psql would merely have to check if it had any bound registers, and if
> so, the next query executed is extended query protocol, and \unbind wipes
> out the binds to send us back to regular mode.
>

what about introduction new syntax for psql variables that should be passed
as bind variables.

like

SELECT * FROM foo WHERE x = $x \g

any time when this syntax can be used, then extended query protocol will be
used

and without any variable, the extended query protocol can be forced by psql
config variable

like

\set EXTENDED_QUERY_PROTOCOL true
SELECT 1;

Regards

Pavel

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