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CREATE EXTENSION hstore_plperl CASCADE;
NOTICE: installing required extension "hstore"
NOTICE: installing required extension "plperl"
SELECT transforms.udt_schema, transforms.udt_name,
routine_schema, routine_name,
group_name, transform_type
FROM information_schema.transforms JOIN information_schema.routines
USING (specific_catalog, specific_schema, specific_name)
ORDER BY 1, 2, 5, 6;
udt_schema | udt_name | routine_schema | routine_name | group_name | transform_type
------------+----------+----------------+------------------+------------+----------------
public | hstore | public | hstore_to_plperl | plperl | FROM SQL
public | hstore | public | plperl_to_hstore | plperl | TO SQL
(2 rows)
-- test perl -> hstore
CREATE FUNCTION test2() RETURNS hstore
LANGUAGE plperl
TRANSFORM FOR TYPE hstore
AS $$
$val = {a => 1, b => 'boo', c => undef};
return $val;
$$;
SELECT test2();
test2
---------------------------------
"a"=>"1", "b"=>"boo", "c"=>NULL
(1 row)
-- test perl -> hstore[]
CREATE FUNCTION test2arr() RETURNS hstore[]
LANGUAGE plperl
TRANSFORM FOR TYPE hstore
AS $$
$val = [{a => 1, b => 'boo', c => undef}, {d => 2}];
return $val;
$$;
SELECT test2arr();
test2arr
--------------------------------------------------------------
{"\"a\"=>\"1\", \"b\"=>\"boo\", \"c\"=>NULL","\"d\"=>\"2\""}
(1 row)
-- check error cases
CREATE OR REPLACE FUNCTION test2() RETURNS hstore
LANGUAGE plperl
TRANSFORM FOR TYPE hstore
AS $$
return 42;
$$;
SELECT test2();
ERROR: cannot transform non-hash Perl value to hstore
CONTEXT: PL/Perl function "test2"
CREATE OR REPLACE FUNCTION test2() RETURNS hstore
LANGUAGE plperl
TRANSFORM FOR TYPE hstore
AS $$
return [1, 2];
$$;
SELECT test2();
ERROR: cannot transform non-hash Perl value to hstore
CONTEXT: PL/Perl function "test2"
DROP FUNCTION test2();
DROP FUNCTION test2arr();
DROP EXTENSION hstore_plperl;
DROP EXTENSION hstore;
DROP EXTENSION plperl;
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