15.00 - WeekNumber_Of_Calendar - Teradata Database

WeekNumber_Of_Calendar

Purpose  

Returns the number of weeks from the beginning of the business calendar to the specified date.

Syntax  

Syntax Elements

calendar_name

A calendar name. The possible values are Teradata, ISO, and COMPATIBLE.

This argument must be a character literal and cannot be a table column or expression. If you do not name a calendar, Teradata uses the calendar for the session.

expression

An expression that results in a DATE, TIMESTAMP, or TIMESTAMP WITH TIME ZONE value.

NULL

The business calendar for the session.

TD_SYSFNLIB

Name of the database where the function is located.

ANSI Compliance

This is a Teradata extension to the ANSI SQL:2011 standard.

Argument Types

The first argument, expression, is defined with the following data types:

DATE

TIMESTAMP

TIMESTAMP WITH TIME ZONE

The second argument, calendar_name, is optional and is defined with the following argument data types:

VARCHAR

NULL

If the argument passed to the function does not match one of these declared data types, an error is returned indicating that the function does not exist.

Result

The result is an INTEGER value. The value 0 means there is a partial week in the year, which is Week0.

Usage Notes

The WeekNumber_Of_Calendar function provides improved performance compared to using the Sys_Calendar.Calendar system view to obtain similar results.

For more information about the view, see Data Dictionary.

Example  

If the current date is January 5, 1901, the following query returns 52 because January 5, 1901, is in week 52 since the start of the Teradata calendar on 1900-01-01:

SELECT TD_SYSFNLIB.WEEKNUMBER_OF_CALENDAR (CURRENT_DATE);

The following query returns 53 because January 5, 1901, is in week 53 since the start of the COMPATIBLE calendar on 1900-01-01:

SELECT TD_SYSFNLIB.WEEKNUMBER_OF_CALENDAR (DATE ‘1901-01-05’, ‘COMPATIBLE’);