postgresql/contrib/ltree_plpython/ltree_plpythonu--1.0.sql

-- make sure the prerequisite libraries are loaded
LOAD 'plpython2';  -- change to plpython3 if that ever becomes the default
SELECT NULL::ltree;


CREATE FUNCTION ltree_to_plpython(val internal) RETURNS internal
LANGUAGE C STRICT IMMUTABLE
AS 'MODULE_PATHNAME';

CREATE TRANSFORM FOR ltree LANGUAGE plpythonu (
    FROM SQL WITH FUNCTION ltree_to_plpython(internal)
);
Add transforms feature This provides a mechanism for specifying conversions between SQL data types and procedural languages. As examples, there are transforms for hstore and ltree for PL/Perl and PL/Python. reviews by Pavel Stěhule and Andres Freund 2015-04-26 22:33:14 +08:00			`-- make sure the prerequisite libraries are loaded`
Use LOAD not actual code execution to pull in plpython library. Commit 866566a690bb9916 is insufficient to prevent dump/reload failures when using transform modules in a database with both plpython2 and plpython3 installed. The reason is that the transform extension scripts use DO blocks as a mechanism to pull in the libpython library before creating the transform function. It's necessary to preload the library because the dynamic loader won't do it for us on every platform, leading to "unresolved symbol" failures when the transform library is loaded. But it's not necessary to execute Python code, and doing so will provoke a multiple-Pythons-are-loaded error even after the preceding commit. To fix, use LOAD instead of a DO block. That requires superuser privilege, but creation of a C function does anyway. It also embeds knowledge of the underlying library name for each PL language; but that's wired into the initdb-time contents of pg_pltemplate too, so that doesn't seem like a large problem either. Note that CREATE TRANSFORM as such doesn't call the language module at all. Per a report from Paul Jones. Back-patch to 9.5 where transform modules were introduced. 2016-01-12 09:06:36 +08:00			`LOAD 'plpython2'; -- change to plpython3 if that ever becomes the default`
Add transforms feature This provides a mechanism for specifying conversions between SQL data types and procedural languages. As examples, there are transforms for hstore and ltree for PL/Perl and PL/Python. reviews by Pavel Stěhule and Andres Freund 2015-04-26 22:33:14 +08:00			`SELECT NULL::ltree;`


			`CREATE FUNCTION ltree_to_plpython(val internal) RETURNS internal`
			`LANGUAGE C STRICT IMMUTABLE`
			`AS 'MODULE_PATHNAME';`

			`CREATE TRANSFORM FOR ltree LANGUAGE plpythonu (`
			`FROM SQL WITH FUNCTION ltree_to_plpython(internal)`
			`);`