diff --git a/database/upgrade/from-bca6b99068cbf1dd4148d6bd5cb60e926162cfe1.sql b/database/upgrade/from-bca6b99068cbf1dd4148d6bd5cb60e926162cfe1.sql
index b44ea05..600673e 100644
--- a/database/upgrade/from-bca6b99068cbf1dd4148d6bd5cb60e926162cfe1.sql
+++ b/database/upgrade/from-bca6b99068cbf1dd4148d6bd5cb60e926162cfe1.sql
@@ -10,7 +10,7 @@
 
 BEGIN;
 
-	DROP FUNCTION IF EXISTS tasks_item_au( ) CASCADE;
+	DROP FUNCTION IF EXISTS tasks_ltc_au( ) CASCADE;
 	CREATE FUNCTION tasks_ltc_au( )
 			RETURNS TRIGGER
 			LANGUAGE PLPGSQL
@@ -34,4 +34,186 @@ BEGIN;
 	CREATE TRIGGER tasks_ltc_au
 		AFTER UPDATE OF ltc_id ON tasks
 		FOR EACH ROW EXECUTE PROCEDURE tasks_ltc_au( );
+
+	DROP FUNCTION IF EXISTS tasks_move( BOOLEAN , INT , BOOLEAN , INT , BOOLEAN , INT[] );
+	CREATE FUNCTION tasks_move( _fromTask BOOLEAN , _fromId INT , _toTask BOOLEAN , _toId INT , _force BOOLEAN , _tasks INT[] )
+			RETURNS INT
+			LANGUAGE PLPGSQL
+			STRICT VOLATILE
+			SECURITY DEFINER
+		AS $tasks_move$
+
+	DECLARE
+		_i		INT;
+		_ltc_source	INT;
+		_ltc_dest	INT;
+
+	BEGIN
+		-- Create the temporary table for tasks
+		PERFORM _tm_create_temp( _tasks );
+
+		-- Make sure all specified tasks exists
+		SELECT INTO _i COUNT( * )
+			FROM _tm_tasks
+				INNER JOIN tasks USING( task_id );
+		IF _i <> array_length( _tasks , 1 ) THEN
+			RETURN 1;
+		END IF;
+
+		-- Make sure all tasks match the specified container
+		PERFORM task_id
+			FROM _tm_tasks
+				INNER JOIN tasks USING( task_id )
+			WHERE ( task_id_parent IS NOT NULL ) <> _fromTask
+				OR ( CASE
+					WHEN task_id_parent IS NULL THEN
+						item_id
+					ELSE
+						task_id_parent
+					END ) <> _fromId;
+		IF FOUND THEN
+			RETURN 2;
+		END IF;
+
+		-- If the source and destination are the same, we're done.
+		IF _fromTask = _toTask AND _fromId = _toId THEN
+			RETURN 0;
+		END IF;
+
+		-- Make sure that the destination exists. Also get the target LTC ID.
+		IF _toTask THEN
+			SELECT INTO _ltc_dest _ltc.ltc_id
+				FROM logical_task_containers _ltc
+					LEFT OUTER JOIN completed_tasks _ct
+						USING( task_id )
+				WHERE _ltc.task_id = _toId AND _ct.task_id IS NULL;
+		ELSE
+			SELECT INTO _ltc_dest ltc_id
+				FROM logical_task_containers
+				WHERE task_id IS NULL;
+			PERFORM item_id FROM items WHERE item_id = _toId;
+		END IF;
+		IF NOT FOUND THEN
+			RETURN 3;
+		END IF;
+
+		-- If we're moving to a task, make sure it isn't a child of any of the
+		-- tasks that are being moved.
+		IF _toTask THEN
+			PERFORM * FROM _tm_tasks _mv
+				INNER JOIN tasks_tree _tree
+					ON _mv.task_id = _tree.task_id_parent
+				WHERE task_id_child = _toId;
+			IF FOUND THEN
+				RETURN 4;
+			END IF;
+		END IF;
+
+		-- Get the source LTC ID.
+		IF _fromTask THEN
+			SELECT INTO _ltc_source ltc_id
+				FROM logical_task_containers
+				WHERE task_id = _fromId;
+		ELSE
+			SELECT INTO _ltc_source ltc_id
+				FROM logical_task_containers
+				WHERE task_id IS NULL;
+		END IF;
+
+		-- If we're changing the LTC, handle dependencies.
+		IF _ltc_source <> _ltc_dest THEN
+			-- Start with external dependencies
+			IF NOT _force THEN
+				-- Check them if we're not forcing the move.
+				PERFORM _tdn.task_id
+					FROM taskdep_nodes _tdn
+						INNER JOIN _tm_tasks _tmt
+							USING( task_id )
+						LEFT OUTER JOIN _tm_tasks _tmt2
+							ON _tmt2.task_id = _tdn.task_id_copyof
+					WHERE _tdn.tnode_depth = 1 AND _tmt2.task_id IS NULL;
+				IF FOUND THEN
+					RETURN 5;
+				END IF;
+			ELSE
+				-- Otherwise, break them.
+				DELETE FROM task_dependencies
+					WHERE taskdep_id IN (
+						SELECT DISTINCT _tdn.taskdep_id
+							FROM taskdep_nodes _tdn
+								INNER JOIN _tm_tasks _tmt
+									USING( task_id )
+								LEFT OUTER JOIN _tm_tasks _tmt2
+									ON _tmt2.task_id = _tdn.task_id_copyof
+							WHERE _tdn.tnode_depth = 1 AND _tmt2.task_id IS NULL
+					);
+			END IF;
+
+			-- Store all internal dependencies, we'll recreate them after
+			-- the tasks have been moved.
+			SET LOCAL client_min_messages=warning;
+			DROP TABLE IF EXISTS _tm_deps;
+			RESET client_min_messages;
+			CREATE TEMPORARY TABLE _tm_deps(
+				task_id	INT ,
+				task_id_depends INT
+			) ON COMMIT DROP;
+			INSERT INTO _tm_deps ( task_id , task_id_depends )
+				SELECT task_id , task_id_depends
+					FROM task_dependencies
+						INNER JOIN _tm_tasks USING ( task_id );
+			DELETE FROM task_dependencies
+				WHERE task_id IN ( SELECT task_id FROM _tm_tasks );
+		END IF;
+
+		-- We're ready to move the tasks themselves.
+		IF _toTask THEN
+			SELECT INTO _i item_id FROM tasks WHERE task_id = _toId;
+		ELSE
+			_i := _toId;
+		END IF;
+		UPDATE tasks SET item_id = _i , ltc_id = _ltc_dest
+			WHERE task_id IN (
+				SELECT task_id FROM _tm_tasks
+			);
+
+		-- Restore deleted dependencies
+		IF _ltc_dest <> _ltc_source THEN
+			INSERT INTO task_dependencies ( task_id , task_id_depends , ltc_id )
+				SELECT task_id , task_id_depends , _ltc_dest
+					FROM _tm_deps;
+		END IF;
+
+		RETURN 0;
+	END;
+	$tasks_move$;
+
+	REVOKE EXECUTE ON FUNCTION tasks_move( BOOLEAN , INT , BOOLEAN , INT , BOOLEAN , INT[] ) FROM PUBLIC;
+	GRANT EXECUTE ON FUNCTION tasks_move( BOOLEAN , INT , BOOLEAN , INT , BOOLEAN , INT[] ) TO :webapp_user;
+
+
+	DROP FUNCTION IF EXISTS _tm_create_temp( INT[] );
+	CREATE FUNCTION _tm_create_temp( _tasks INT[] )
+			RETURNS VOID
+			LANGUAGE PLPGSQL
+			STRICT VOLATILE
+			SECURITY INVOKER
+		AS $_tm_create_temp$
+	DECLARE
+		_i	INT;
+	BEGIN
+		SET LOCAL client_min_messages=warning;
+		DROP TABLE IF EXISTS _tm_tasks;
+		RESET client_min_messages;
+
+		CREATE TEMPORARY TABLE _tm_tasks(
+			task_id	INT
+		) ON COMMIT DROP;
+		FOR _i IN array_lower( _tasks , 1 ) .. array_upper( _tasks , 1 )
+		LOOP
+			INSERT INTO _tm_tasks( task_id ) VALUES ( _tasks[ _i ] );
+		END LOOP;
+	END;
+	$_tm_create_temp$;
+	REVOKE EXECUTE ON FUNCTION _tm_create_temp( INT[] ) FROM PUBLIC;
 COMMIT;