Hi
I'm making my first steps in C functions. I want to avoid doing all the
SQL job in them, pl/pgsql looks a better choice. I tried to do this by
passing opened cursor from pl/pgsql function to C function.
Here is simple C function:
#include <server/postgres.h>
#include <server/executor/spi.h>
PG_FUNCTION_INFO_V1(test2);
Datum test2(PG_FUNCTION_ARGS)
{ Portal p; int n; p=SPI_cursor_find("xxx"); if(!p) elog(ERROR,"Cursor error"); SPI_cursor_fetch(p,true,1);
n=SPI_processed; PG_RETURN_INT32(n);
}
And pl/pgsql one:
CREATE OR REPLACE FUNCTION test() returns integer AS '
DECLARE _m CURSOR FOR select id from some_table limit 1; n integer;
BEGIN _m=''xxx''; open _m; n=test2(); close _m; return n;
END;
' language 'plpgsql';
select test();
I don't understand ERROR message at all: ERROR: SPI_prepare() failed on "SELECT $1 "
This error is raised when trying to execute SPI_cursor_fetch. What does
it mean? What does the SPI_prepare have to already opened cursor?
Where can I find better SPI documentation than "Postgresql Server
Programming" ?
Regards,
Tomasz Myrta