Re: create trigger (can't compile example, problem with include files)

On Thursday 14 December 2000 18:54, Robert B. Easter wrote:
> Trigger functions, no matter what language, have be RETURNS OPAQUE.
>
> Here is an example (in the PostgreSQL docs):
> http://www.comptechnews.com/~reaster/postgres/triggers20290.htm
>
> Sorry I can't help more as I've never actually used C triggers, just
> PL/pgSQL ones.
>

Admitting I have not tried using C triggers, I decided to try the example at
the url above.  I saved the example C trigger to a file called ttest.c and
compile it with:

gcc -shared -I/usr/local/pgsql/include ttest.c -o ttest.o

(I hope that is the right command), then I got this:

reaster@comptechnews:~/prog/triggers$ gcc -shared -I/usr/local/pgsql/include
ttest.c -o ttest.o
In file included from ttest.c:1:
/usr/local/pgsql/include/executor/spi.h:17: nodes/primnodes.h: No such file
or directory
/usr/local/pgsql/include/executor/spi.h:18: nodes/relation.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:19: nodes/execnodes.h: No such file
or directory
/usr/local/pgsql/include/executor/spi.h:20: nodes/plannodes.h: No such file
or directory
/usr/local/pgsql/include/executor/spi.h:21: catalog/pg_proc.h: No such file
or directory
/usr/local/pgsql/include/executor/spi.h:22: catalog/pg_type.h: No such file
or directory
/usr/local/pgsql/include/executor/spi.h:23: tcop/pquery.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:24: tcop/tcopprot.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:25: tcop/utility.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:26: tcop/dest.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:27: nodes/params.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:28: utils/fcache.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:29: utils/datum.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:30: utils/syscache.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:31: utils/portal.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:32: utils/builtins.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:33: catalog/pg_language.h: No such
file or directory
/usr/local/pgsql/include/executor/spi.h:34: access/heapam.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:35: access/xact.h: No such file or
directory
/usr/local/pgsql/include/executor/spi.h:36: executor/executor.h: No such file
or directory
/usr/local/pgsql/include/executor/spi.h:37: executor/execdefs.h: No such file
or directory
In file included from ttest.c:2:
/usr/local/pgsql/include/commands/trigger.h:16: nodes/execnodes.h: No such
file or directory
/usr/local/pgsql/include/commands/trigger.h:17: nodes/parsenodes.h: No such
file or directory
reaster@comptechnews:~/prog/triggers$


I compared /usr/local/pgsql/include with
/usr/src/postgresql-7.0.3/src/include and found that the src has more include
files so that I tried:

reaster@comptechnews:~/prog/triggers$ gcc -shared -I/usr/local/pgsql/include
-I/usr/src/postgresql-7.0.3/src/include ttest.c -o ttest.o
ttest.c: In function `trigf':
ttest.c:17: `WARN' undeclared (first use in this function)
ttest.c:17: (Each undeclared identifier is reported only once
ttest.c:17: for each function it appears in.)


Anyhow, can someone help me here with these include files and the missing
WARN define?


> On Thursday 14 December 2000 18:04, Sandeep Joshi wrote:
> > I am trying to use "triggers". I get an error after "create trigger".
> > Does anybody know why?
> >
> >  create function insert_into_db2 RETURNS int AS
> > '/work/posgresql/lib/libpq.so' language 'C';
> >
> >  create trigger trial before insert or update on db1user for each row
> > execute procedure  insert_into_db2();
> >
> >  ERROR:  CreateTrigger: function insert_into_db2() must return OPAQUE
> >
> > Does anybody know why?
> >
> > Also, if a function is enforced to return OPAQUE then  what is the
> > "RETURNS" clause?
> >
> >
> > One more question,
> >      If a trigger does not succeed then I want to ABORT transaction, is
> > it possible? how?
> >
> >
> > - Sandeep

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