/***********************************************************************/

/*  Returns its argument saying it is not a constant.                  */

/***********************************************************************/

my_bool noconst_init(UDF_INIT *initid, UDF_ARGS *args, char *message)

{

	if (args->arg_count != 1 || args->arg_type[0] != STRING_RESULT) {

		strcpy(message, "noconst unique argument must be a string");

		return true;

	} // endif arg

	initid->const_item = false;    // The trick!

	return false;

} // end of noconst_init

char *noconst(UDF_INIT *initid, UDF_ARGS *args, char *result,

	unsigned long *res_length, char *, char *)

{

	return args->args[0];

} // end of noconst

MariaDB [test]> create table t1 (

    -> n int key not null auto_increment,

    -> msg char(20) as (noconst('Hello World')) virtual);

Query OK, 0 rows affected (0.06 sec)

MariaDB [test]> insert into t1() values();

Query OK, 1 row affected (0.01 sec)

MariaDB [test]> select * from t1;

+---+-------------+

| n | msg         |

+---+-------------+

| 1 | Hello World |

+---+-------------+

1 row in set (0.00 sec)

void udf_handler::cleanup()

{

  if (!not_original)

  {

    if (initialized)

    {

      if (u_d->func_deinit != NULL)

      {

        Udf_func_deinit deinit= u_d->func_deinit;

        (*deinit)(&initid);

      }

      free_udf(u_d);

      initialized= FALSE;

    }

    if (buffers)				// Because of bug in ecc

      delete [] buffers;

    buffers= 0;

  }

}