Re: [HACKERS] SQL procedures - Mailing list pgsql-hackers

From Andrew Dunstan
Subject Re: [HACKERS] SQL procedures
Date
Msg-id b24839d5-0190-0958-f5f5-7c332a2c22b8@2ndQuadrant.com
Whole thread Raw
In response to Re: [HACKERS] SQL procedures  (Corey Huinker <corey.huinker@gmail.com>)
Responses Re: [HACKERS] SQL procedures  (Craig Ringer <craig@2ndquadrant.com>)
List pgsql-hackers

On 11/22/2017 02:39 PM, Corey Huinker wrote:
>
>
>     T-SQL procedures returns data or OUT variables.
>
>     I remember, it was very frustrating
>
>     Maybe first result can be reserved for OUT variables, others for
>     multi result set
>
>
> It's been many years, but if I recall correctly, T-SQL returns a
> series of result sets, with no description of the result sets to be
> returned, each of which must be consumed fully before the client can
> move onto the next result set. Then and only then can the output
> parameters be read. Which was very frustrating because the OUT
> parameters seemed like a good place to put values for things like
> "result set 1 has 205 rows" and "X was false so we omitted one result
> set entirely" so you couldn't, y'know easily omit entire result sets. 
>



Exactly. If we want to handle OUT params this way they really need to be
the first resultset for just this reason. That could possibly be done by
the glue code reserving a spot in the resultset list and filling it in
at the end of the procedure.

cheers

andrew

-- 
Andrew Dunstan                https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



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