PERIOD (DATE) / PERIOD(TIME) / PERIOD(TIMESTAMP) - Advanced SQL Engine - Teradata Database

C Data Type Definition

typedef int PDT_HANDLE;

Usage

Use the PDT_HANDLE data type when passing or returning a PERIOD(DATE), PERIOD(TIME(n)), PERIOD(TIME(n) WITH TIME ZONE), PERIOD(TIMESTAMP(n)), or PERIOD(TIMESTAMP(n) WITH TIME ZONE)) argument or return type.

The fractional seconds precision defined for the SQL PERIOD(TIME(n)), PERIOD(TIME(n) WITH TIME ZONE), PERIOD(TIMESTAMP(n)), or PERIOD(TIMESTAMP(n) WITH TIME ZONE)) type applies to the input arguments and return argument of a function. A value outside the valid range of values produces an error.

All PERIOD(TIME(n)) and PERIOD(TIMESTAMP(n)) values passed to a UDF are in Universal Coordinated Time (UTC), and all PERIOD(TIME(n)) and PERIOD(TIMESTAMP(n)) values that are returned from a UDF must be in UTC.

The PERIOD(TIME(n) WITH TIME ZONE) and PERIOD(TIMESTAMP(n) WITH TIME ZONE) types have time zone fields, zone_hour and zone_minute, that have an internal form and an external form. When input arguments with these types are passed to a UDF, the values must be in internal form. Similarly, return arguments with these types must be in internal form.

• TIMEZONE_EXTERNAL_TO_INTERNAL(s,h,m,i)

  where:

  Input Parameter	Description
  s	a BYTEINT value to set the sign for i.
  h	a BYTEINT value to set the hour offset for i.
  m	a BYTEINT value to set the minute offset for i.
  i	a pointer to an ANSI_Time_Wzone or a pointer to an ANSI_TimeStamp_Wzone.

The largest value for negative offsets is -12:59. The largest value for positive offsets is +14:00.

This representation results in two representations of UTC, that is +00:00 and -00:00. This mirrors the internal representation which uses both representations for display purposes.

For details on Period types, see Teradata Vantage™ - Data Types and Literals, B035-1143.

Here is an example using a PERIOD(DATE) in a UDF definition and PDT_HANDLE in a C function declaration.

CREATE FUNCTION F1 (
  A PERIOD(DATE) )
RETURNS PERIOD(DATE)
 ...;

void f1( PDT_HANDLE *a,
         PDT_HANDLE *result,
   ... )
{  ... }