Re: Using substr with user defined types

Thus spake Tom Lane
> darcy(at)druid(dot)net (D'Arcy J.M. Cain) writes:
> > create function chkpass_rout(opaque)
> > returns opaque
> > as '/usr/pgsql/modules/chkpass.so'
> > language 'c';
>
> > Here is what happens.
>
> > soccer=> select chkpass_rout('hello'::chkpass);
> > ERROR: typeidTypeRelid: Invalid type - oid = 0
>
> Functions that you intend to invoke as ordinary functions shouldn't have
> inputs or outputs declared "opaque", because the expression evaluation
> code won't have any idea what to do. When you are building functions
> that will be the input or output converters for a datatype, you can read
> "opaque" as meaning "C string", so for example the input converter takes
> opaque and returns your type. But otherwise you don't want to be using
> opaque. Perhaps what you wanted here was
> "create function chkpass_rout(chkpass) returns text".

OK, I tried this.

load '/usr/pgsql/modules/chkpass.so';

--
-- Input and output functions and the type itself:
--

create function chkpass_in(opaque)
returns opaque
as '/usr/pgsql/modules/chkpass.so'
language 'c';

create function chkpass_out(opaque)
returns opaque
as '/usr/pgsql/modules/chkpass.so'
language 'c';

create type chkpass (
internallength = 16,
externallength = 13,
input = chkpass_in,
output = chkpass_out
);

create function raw(chkpass)
returns text
as '/usr/pgsql/modules/chkpass.so', 'chkpass_rout'
language 'c';

Then I did this.

darcy=> select 'hello'::chkpass;
?column?
--------------
:Rd1xqQo0.2V6.
(1 row)

darcy=> select raw('hello'::chkpass);
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.

I added an fprintf to stderr as the first statement in chkpass_rout() which
doesn't print so I am pretty sure it isn't my function. The same thing
happens if I create a table with a chkpass type. Any ideas?

--
D'Arcy J.M. Cain <darcy(at){druid|vex}.net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.