CREATE TABLE TEST
 (ID         INTEGER  NOT NULL,
  ...
  DATEMODIF  DATE     NOT NULL  DEFAULT CURRENT DATE
 )

DATEMODIF  DATE     NOT NULL GENERATED ALWAYS AS CURRENT DATE

#include <string.h> 
#include <stdlib.h> 
#include <time.h> 
#include <sqludf.h> 
 
#ifdef __cplusplus
extern "C"
#endif
void SQL_API_FN get_date( 
        SQLUDF_DATE *result,      /* output */ 
        /* null indicators */ 
        SQLUDF_NULLIND *result_ind, 
        SQLUDF_TRAIL_ARGS) 
{ 
  struct tm *lt;
  time_t t;

  time(&t);
  lt = localtime(&t);
  sprintf(result, "%.4d-%.2d-%.2d\n", lt->tm_year+ 1900 , lt->tm_mon, lt->tm_mday);
  *result_ind =  0 ; 
}

CREATE FUNCTION get_date()
RETURNS DATE
EXTERNAL NAME 'get_date!get_date'
LANGUAGE C 
PARAMETER STYLE SQL
DETERMINISTIC
FENCED
NO SQL
NO EXTERNAL ACTION;

DATEMODIF  DATE     NOT NULL GENERATED ALWAYS AS (get_date())