Parameter Lists in Functions that User Period Types - Analytics Database - Teradata Vantage

UDFs can define Period arguments and return values. A UDF passes a Period argument by a handle.

Here is an example of how to declare a scalar function that uses Period types:

/*****  C source file name: udfsamp.c  *****/
   
#define SQL_TEXT Latin_Text
#include <sqltypes_td.h>
   
void do_something( PDT_HANDLE          *aPDT,
                  PDT_HANDLE          *resultPDT,
                  char                sqlstate[6] )
{
     ...
}

The corresponding CREATE FUNCTION statement looks like this:

CREATE FUNCTION DO_SOMETHING(A PERIOD(TIMESTAMP))
        RETURNS PERIOD(DATE)
        LANGUAGE C
        NO SQL
        PARAMETER STYLE TD_GENERAL
        EXTERNAL NAME 'CS!udfsamp!td_udf/udfsamp.c';

For details on the PDT_HANDLE C data type, see C Data Types.