BEGIN;
ALTER TABLE xml_nodes  ADD COLUMN column_new TEXT;
UPDATE xml_nodes SET column_new = nodedata;
ALTER TABLE xml_nodes DROP COLUMN nodedata;
ALTER TABLE xml_nodes RENAME column_new TO nodedata;
COMMIT;

BEGIN;
ALTER TABLE xml_nodes_revisions ADD COLUMN column_new TEXT;
UPDATE xml_nodes_revisions SET column_new = nodedata;
ALTER TABLE xml_nodes_revisions DROP COLUMN nodedata;
ALTER TABLE xml_nodes_revisions RENAME column_new TO nodedata;
COMMIT;

BEGIN;
ALTER TABLE xml_queryresult ADD COLUMN column_new TEXT;
UPDATE xml_queryresult SET column_new = queryresult_string;
ALTER TABLE xml_queryresult DROP COLUMN queryresult_string;
ALTER TABLE xml_queryresult RENAME column_new TO queryresult_string;
COMMIT;

BEGIN;
ALTER TABLE xml_path_index ADD COLUMN column_new TEXT;
UPDATE xml_path_index SET column_new = nodedata;
ALTER TABLE xml_path_index DROP COLUMN nodedata;
ALTER TABLE xml_path_index RENAME column_new TO nodedata;
COMMIT;