Hive date function to achieve day of week

Question

I\'m looking for a workaround or hive date functions that gives day of the week ,

Sunday - 1
Monday - 2
Tuesday - 3
Wednesday - 4
Thursday - 5
Friday - 6
Sat         


        

Answer 1

From Hive 2.2 there is another possibility:

hive> select extract(dayofweek FROM your_date) FROM your_table;

Answer 2

select pmod(datediff(your_date,'1900-01-07'),7) + 1 as WeekDay from your_table

• arbitrary start date picked (1900-01-07)
• calculates the mod 7 day of week (plus 1 to start at 1 instead of zero)

Answer 3

Expanding on iggy's answer, here is the query to get the days of the week. Adjust the query to set the first day of the week as necessary.

SELECT current_date AS `Date`,
       CASE date_format(current_date,'u')
           WHEN 1 THEN 'Mon'
           WHEN 2 THEN 'Tues'
           WHEN 3 THEN 'Wed'
           WHEN 4 THEN 'Thu'
           WHEN 5 THEN 'Fri'
           WHEN 6 THEN 'Sat'
           WHEN 7 THEN 'Sun'
END AS day_of_week

Answer 4

As I said you need to write a UDF which will accept a string as parameter and return a string. Inside the UDF you need to do these steps:

1.) Parse the input string using SimpleDateFormat(YYYYMMDD)

2.) Use the Below code to get the day of week:

Calendar c = Calendar.getInstance();
c.setTime(yourDate);
int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);

3.) Use this dayOfWeek value in a case statement to get your weekday String and return that string.

Hope this helps...!!!

Answer 5

Consider using from_unixtime(your date,'u') - this will return day number of week starting from Monday=1. If your date is not in unixtime format, you can use the following instead:

from_unixtime(unix_timestamp('20140112','yyyyMMdd'),'u')

see: http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html for simple date format documentation.

Answer 6

You can now use date_format (Hive 1.2):

hive> select date_format('2016-12-01' ,'u');
OK
4