I sent this a while ago to general and then
hackers and got no response.
The question is whether to qualify the return value
of a function when it returns a domain with
a check clause.
I believe it should--otherwise the domain is
only useful on insert and is not acting
like a full fledged type. However, I suspect
that there is no underlying support for
type checks in the general system.
Elein
----- Forwarded message from elein <elein@varlena.com> -----
I can create a function with a domain and
define it to return a domain.
The parameter is checked to see if it qualifies
in the constraint of the domain, however, the
return value is not.
Is this a bug? Is the author of the function
responsible for re-inforcing the constraint
at runtime?
This is the test case in 7.4:
=# create domain one2hundred AS integer
-# DEFAULT '1' CONSTRAINT email_domain check( VALUE > 0 AND VALUE <=100 );
CREATE DOMAIN
=#
=# create function gb52_add( one2hundred )
-# returns one2hundred as
-# '
'# BEGIN
'# RETURN $1 + 10;
'# END;
'# ' language 'plpgsql';
CREATE FUNCTION
=#
=# select gb52_add( 80);gb52_add
---------- 90
(1 row)
=# select gb52_add( 100);gb52_add
---------- 110
(1 row)
=# select gb52_add( 90);gb52_add
---------- 100
(1 row)
=# select gb52_add( 91);gb52_add
---------- 101
(1 row)
=# select gb52_add( 191);
ERROR: value for domain one2hundred violates check constraint "email_domain"
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----- End forwarded message -----
