-- Add to the search path the schema
SET search_path TO public,cartodb,cdb_dataservices_client;
CREATE TABLE my_table(cartodb_id int);
INSERT INTO my_table (cartodb_id) VALUES (1);
-- Mock the server functions
CREATE OR REPLACE FUNCTION cdb_dataservices_server._DST_ConnectUserTable(username text, orgname text, user_db_role text, input_schema text, dbname text, table_name text)
RETURNS cdb_dataservices_client.ds_fdw_metadata AS $$
BEGIN
  RETURN ('dummy_schema'::text, 'dummy_table'::text, 'dummy_server'::text);
END;
$$ LANGUAGE 'plpgsql';
CREATE OR REPLACE FUNCTION cdb_dataservices_server._DST_GetReturnMetadata(username text, orgname text, function_name text, params json)
RETURNS cdb_dataservices_client.ds_return_metadata AS $$
BEGIN
  RETURN (Array['total_pop'], Array['double precision']);
END;
$$ LANGUAGE 'plpgsql';
CREATE OR REPLACE FUNCTION cdb_dataservices_server._DST_FetchJoinFdwTableData(username text, orgname text, table_schema text, table_name text, function_name text, params json)
RETURNS RECORD AS $$
BEGIN
  RETURN (23.4::double precision, 1::int);
END;
$$ LANGUAGE 'plpgsql';
CREATE OR REPLACE FUNCTION cdb_dataservices_server._DST_DisconnectUserTable(username text, orgname text, table_schema text, table_name text, servername text)
RETURNS boolean AS $$
BEGIN
  RETURN true;
END;
$$ LANGUAGE 'plpgsql';
SELECT CDB_Conf_SetConf('api_keys_postgres', '{"username": "test_user", "permissions": [""]}');
 cdb_conf_setconf 
------------------
 
(1 row)

-- Create a sample user table
CREATE TABLE user_table (cartodb_id int, the_geom geometry);
INSERT INTO user_table(cartodb_id, the_geom) VALUES (1, '0101000020E6100000F74FC902E07D52C05FE24CC7654B4440');
INSERT INTO user_table(cartodb_id, the_geom) VALUES (2, '0101000020E6100000F74FC902E07D52C05FE24CC7654B4440');
INSERT INTO user_table(cartodb_id, the_geom) VALUES (3, '0101000020E6100000F74FC902E07D52C05FE24CC7654B4440');
-- Prepare a table with the total_pop column
SELECT cdb_dataservices_client._DST_PrepareTableOBS_GetMeasure('my_table_dst', '{"dummy":"dummy"}'::json);
 _dst_preparetableobs_getmeasure 
---------------------------------
 t
(1 row)

-- The table should now exist and be empty
SELECT * FROM my_table_dst;
 cartodb_id | the_geom | total_pop 
------------+----------+-----------
(0 rows)

-- Populate the table with measurement data
SELECT cdb_dataservices_client._DST_PopulateTableOBS_GetMeasure('user_table', 'my_table_dst', '{"dummy":"dummy"}'::json);
 _dst_populatetableobs_getmeasure 
----------------------------------
 t
(1 row)

-- The table should now show the results
SELECT * FROM my_table_dst;
 cartodb_id |                      the_geom                      | total_pop 
------------+----------------------------------------------------+-----------
          1 | 0101000020E6100000F74FC902E07D52C05FE24CC7654B4440 |      23.4
          2 | 0101000020E6100000F74FC902E07D52C05FE24CC7654B4440 |          
          3 | 0101000020E6100000F74FC902E07D52C05FE24CC7654B4440 |          
(3 rows)

-- Clean tables
DROP TABLE my_table_dst;
SELECT CDB_Conf_RemoveConf('api_keys_postgres');
 cdb_conf_removeconf 
---------------------
 
(1 row)