hive equivalent for TD_WEEK_OF_CALENDAR - sql

Question

I am trying to implement a query already written for Teradata in Hive and was using weekofyear() until now as a replacement of TD_WEEK_OF_CALENDAR method which returns an INTEGER value representing the number of full weeks since and including the week of 01/01/1900, where the first partial week is 0.
I couldn't find any other predefined UDF in Hive related to this method. Even for writing a custom UDF in Java, I was not able to get the exact logic of TD_WEEK_OF_CALENDAR.
Can someone please help on this?

Answer 1

This can be achieved using the Joda time functions. But Hive doesn't support Joda time Jars and you need to explicitly add the joda-time jars to your hive lib folder.
The function TD_WEEK_OF_CALENDAR treats Sunday as first day of week and Saturday as last whereas the joda-time function getDayOfWeek() treats Sunday as last day of the week giving its number as 7 which pulls Sunday into the same week.
This below code would to the needful
public Text evaluate(Text input) {
if(null != input){
String date = input.toString();
StringTokenizer st = new StringTokenizer(date, "-");
int year = Integer.parseInt(st.nextToken());
int month = Integer.parseInt(st.nextToken());
int day = Integer.parseInt(st.nextToken());
DateTime dateTime1 = new DateTime(1900, 1, 1, 0, 0, 0, 0);
DateTime dateTime2 = new DateTime(year, month, day, 0, 0, 0, 0);
int weeksDiff = dateTime2.getDayOfWeek() == 7 ? Weeks.weeksBetween(
dateTime1, dateTime2).getWeeks() + 1 : Weeks.weeksBetween(
dateTime1, dateTime2).getWeeks();
String weeks = weeksDiff + "";
return new Text(weeks);
} else {
return null;
}