Скачать или смотреть SQL Tricks: Unusual Ways to Determine the Day of the Week

Hello everyone,

In this video we will see how you can get day of the week for any given date in SQL.

Video timeline :

00:00 Introduction
00:20 First Method - use in-built function like to_char
01:08 Second Method - use date dimension table
01:50 Third Method - use custom user defined function

Queries used in the tutorial:

/* first method : to_char */
select current_date as c1,
to_char(current_date,'Day') as c2;

/* second method : date dimension */
select current_date as c1,
day_name as c2
from dim_calendar
where
"date"= current_date;

/* third method : custom function */
CREATE OR REPLACE FUNCTION fn_dayname(my_date DATE)
RETURNS varchar
STABLE
AS $$
import calendar
return calendar.day_name[my_date.weekday()]
$$ LANGUAGE plpythonu;

select current_date as c1, fn_dayname(c1) as c2;

Hope you find this video helpful.