From 28376ffecb0aa61f304b340356aa1cdf219efba8 Mon Sep 17 00:00:00 2001
From: Raul Marin <git@rmr.ninja>
Date: Wed, 30 Oct 2019 13:53:56 +0100
Subject: [PATCH] CDB_Federated_Table_Register works to refresh a table

---
 scripts-available/CDB_FederatedServerTables.sql |  7 ++++++-
 test/CDB_FederatedServerTables.sql              | 16 ++++++++++++++++
 test/CDB_FederatedServerTables_expect           |  5 ++++-
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/scripts-available/CDB_FederatedServerTables.sql b/scripts-available/CDB_FederatedServerTables.sql
index 30750ab..bd93445 100644
--- a/scripts-available/CDB_FederatedServerTables.sql
+++ b/scripts-available/CDB_FederatedServerTables.sql
@@ -66,10 +66,11 @@ $$ LANGUAGE SQL;
 -- Sets up a Federated Table
 --
 -- Precondition: the federated server has to be set up via
--- CDB_SetUp_PG_Federated_Server
+-- CDB_Federated_Server_Register_PG
 --
 -- Postcondition: it generates a view in the schema of the user that
 -- can be used through SQL and Maps API's.
+-- If the table was already exported, it will be dropped and re-imported
 --
 -- E.g:
 -- SELECT cartodb.CDB_SetUp_PG_Federated_Table(
@@ -113,6 +114,10 @@ BEGIN
     END IF;
 
     -- Import the foreign table
+    -- Drop the old view / table if there was one
+    IF EXISTS (SELECT 1 FROM information_schema.tables WHERE  table_schema = local_schema AND table_name = remote_table) THEN
+        EXECUTE @extschema@.CDB_Federated_Table_Unregister(server, remote_schema, remote_table);
+    END IF;
     EXECUTE FORMAT ('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I;', remote_schema, remote_table, server_internal, local_schema);
     src_table := format('%I.%I', local_schema, remote_table);
     
diff --git a/test/CDB_FederatedServerTables.sql b/test/CDB_FederatedServerTables.sql
index 1072f47..11986f5 100644
--- a/test/CDB_FederatedServerTables.sql
+++ b/test/CDB_FederatedServerTables.sql
@@ -88,6 +88,22 @@ Select 'list_remotes2', CDB_Federated_Server_List_Registered_Tables(
     remote_schema => 'remote_schema'
 );
 
+-- Reregistering R2 with different parameters should work
+SELECT 'R3', cartodb.CDB_Federated_Table_Register(
+    server => 'loopback',
+    remote_schema => 'remote_schema',
+    remote_table => 'remote_geom2',
+    id_column => 'id',
+    geom_column => 'geom',
+    local_name => 'different_name'
+    );
+
+-- The old view should dissapear
+SELECT 'S3_old', cartodb_id, ST_AsText(the_geom_webmercator), another_field FROM "myFullTable";
+-- And the new appear
+SELECT 'S3_new', cartodb_id, ST_AsText(the_geom_webmercator), another_field FROM different_name;
+
+-- Deregistering the first table
 SELECT 'U1', CDB_Federated_Table_Unregister(
     server => 'loopback',
     remote_schema => 'remote_schema',
diff --git a/test/CDB_FederatedServerTables_expect b/test/CDB_FederatedServerTables_expect
index 0d0f175..3badec2 100644
--- a/test/CDB_FederatedServerTables_expect
+++ b/test/CDB_FederatedServerTables_expect
@@ -17,7 +17,10 @@ V2| SELECT t.id AS cartodb_id,
 S2|3|POINT(3 3)|patata
 list_remotes2|(remote_geom2,"public.""myFullTable""")
 list_remotes2|(remote_geom,public.remote_geom)
+R3|
+ERROR:  relation "myFullTable" does not exist at character 82
+S3_new|3|POINT(333958.472379821 334111.17140196)|patata
 U1|
 ERROR:  relation "remote_geom" does not exist at character 71
-list_remotes3|(remote_geom2,"public.""myFullTable""")
+list_remotes3|(remote_geom2,public.different_name)
 D1|