DROP EXTENSION IF EXISTS www_fdw CASCADE; CREATE EXTENSION www_fdw; CREATE SERVER www_fdw_server_test FOREIGN DATA WRAPPER www_fdw OPTIONS (uri 'http://localhost:7777', request_serialize_callback 'test_request_serialize_callback'); CREATE USER MAPPING FOR current_user SERVER www_fdw_server_test; CREATE FOREIGN TABLE www_fdw_test ( title text, link text, snippet text ) SERVER www_fdw_server_test; CREATE TABLE IF NOT EXISTS post_data ( key text NOT NULL UNIQUE, value text ); DELETE FROM post_data; INSERT INTO post_data VALUES ('data','title=post_title'),('content_type',null); CREATE OR REPLACE FUNCTION test_request_serialize_callback(options WWWFdwOptions, quals text, INOUT url text, INOUT post WWWFdwPostParameters) AS $$ BEGIN RAISE DEBUG 'options parameter: %', options; RAISE DEBUG 'quals parameter: %', quals; RAISE DEBUG 'url parameter: %', url; RAISE DEBUG 'post parameter: %', post; post.post := true; post.data := (SELECT value FROM post_data WHERE key='data'); post.content_type := (SELECT value FROM post_data WHERE key='content_type'); RAISE DEBUG 'new post %', post; END; $$ LANGUAGE PLPGSQL;