We cannot to declare variable with referenced type on other composite variable. This limit is probably artificial, because any composite type is any type too in PostgreSQL.
The issue:
referencing on composite variables doesn't work
do $$ declare x int; y x%type; begin end; $$; -- ok do $$ declare x pg_class; y x%type; begin end; $$; -- invalid type name "x%type" do $$ declare x pg_class; y x%rowtype; begin end; $$; -- relation "x" does not exist
The %ROWTYPE needs a record in pg_class. Probably we should not to change it. The change can bring a compatibility issues. So there are two possibilities:
1. %TYPE can be used for any kind of variables. This behave will be consistent with polymorphic parameters - we have "anyelement", and we have not "anyrow".
2. introduce new keyword - %RECTYPE .. it can work, but there will be gap between polymorphic parameters.
Comments, notices?
Hi
I am sending patch that enables to use references to polymorphic parameters of row types. Another functionality is possibility to get array or element type of referenced variable. It removes some gaps when polymorphic parameters are used.
create type test_composite_type as (x int, y int); create or replace function test_simple(src anyelement) returns anyelement as $$ declare dest src%type; begin dest := src; return dest; end; $$ language plpgsql; select test_simple(10); test_simple ------------- 10 (1 row)