Re: enhance SPI to support EXECUTE commands

On 2019/9/5 15:09, Pavel Stehule wrote:
>
>
> čt 5. 9. 2019 v 8:39 odesílatel Quan Zongliang
> <zongliang(dot)quan(at)postgresdata(dot)com
> <mailto:zongliang(dot)quan(at)postgresdata(dot)com>> napsal:
>
> Dear hackers,
>
> I found that such a statement would get 0 in PL/pgSQL.
>
> PREPARE smt_del(int) AS DELETE FROM t1;
> EXECUTE 'EXECUTE smt_del(100)';
> GET DIAGNOSTICS j = ROW_COUNT;
>
> In fact, this is a problem with SPI, it does not support getting result
> of the EXECUTE command. I made a little enhancement. Support for the
> number of rows processed when executing INSERT/UPDATE/DELETE statements
> dynamically.
>
>
> Is there some use case for support this feature?
>
A user deletes the data in PL/pgSQL using the above method, hoping to do
more processing according to the number of rows affected, and found that
each time will get 0.

Sample code:
PREPARE smt_del(int) AS DELETE FROM t1 WHERE c=$1;
EXECUTE 'EXECUTE smt_del(100)';
GET DIAGNOSTICS j = ROW_COUNT;

IF j=1 THEN
do something
ELSIF j=0 THEN
do something

Here j is always equal to 0.

Regards

> Regards
>
> Pavel
>
>
> Regards,
> Quan Zongliang
>