declare
    object_exists exception;
    pragma exception_init (object_exists , -00955);
begin
    execute immediate 'ALTER TABLE CONF_RESTRICAO_CANALVENTA MODIFY (CONFRESTRICAOCANALVENTA_ID NUMBER(15, 0) )';
    execute immediate 'ALTER TABLE CONF_RESTRICAO_EXCECAO MODIFY (CONFRESTRICAOCANALVENTA_ID NUMBER(15, 0) )';
    execute immediate 'ALTER TABLE CONF_RESTRICAO_PTOVTA MODIFY (CONFRESTRICAOCANALVENTA_ID NUMBER(15, 0) )';
    exception when object_exists then null;
end;