In mysql How to find number of sundays in a month - mysql

Question

In mysql how to find number of sundays in month by usnig month in where clause
Ex:
month(log_date)=month(now());
month(log_date) = 12;
output: 5 sundays

Answer 1

Possible way to do it which avoids using any tables. This finds the number of days in the month, and depending on that and what day of the week the last day is then it just returns a value
SELECT CASE DAYOFMONTH(LAST_DAY(NOW()))
WHEN 31 THEN
CASE DAYOFWEEK(LAST_DAY(NOW()))
WHEN 1 THEN 5
WHEN 2 THEN 5
WHEN 3 THEN 5
ELSE 4
END
WHEN 30 THEN
CASE DAYOFWEEK(LAST_DAY(NOW()))
WHEN 1 THEN 5
WHEN 2 THEN 5
ELSE 4
END
WHEN 29 THEN
CASE DAYOFWEEK(LAST_DAY(NOW()))
WHEN 1 THEN 5
ELSE 4
END
ELSE 4
END

Answer 2

SQL query for get total sunday in given month from DB
USE BETWEEN :- BETWEEN operator selects values within a given range.
Note :- DAYOFWEEK actually returns 1 for Sunday
SELECT count(*) AS total_sunday FROM `table` WHERE DAYOFWEEK(`date`) = 1 BETWEEN '2017-11-01' AND '2017-11-30';

Answer 3

In mysql just copy and paste the query given below. It will give you number of Sundays in current month.
WITH RECURSIVE offdays as(
SELECT
LAST_DAY(CURDATE()-INTERVAL 1 MONTH) + INTERVAL 1 DAY AS `Date`,
DAYNAME(LAST_DAY(CURDATE()-INTERVAL 1 MONTH) + INTERVAL 1 DAY) AS `DayName`
UNION ALL
SELECT `Date` + INTERVAL 1 DAY, DAYNAME(`Date` + INTERVAL 1 DAY)
FROM offdays WHERE `DATE` < LAST_DAY(CURDATE())
) SELECT count(*) FROM offdays where DAYNAME(DATE) = 'Sunday';
you will get number of sundays in current month. Just replace the CURDATE() with any date. The query will give you the number of Sundays of the month of the date supplied.

Answer 4

Try this function, you use like
count_days_in_month($date_month,$day_idx);
$day_idx is 1 - 7 where Sunday is 1, Saturday is 7
eg.
select count_days_in_month('2020-02-01',1);
delimiter //
create or replace function count_days_in_month(input_date DATE,dayindex INT)
returns INT
DETERMINISTIC
BEGIN
declare start_day_idx INT default (select dayofweek( date_sub(input_date,INTERVAL (DAYOFMONTH(input_date)-1) DAY )) from dual);
declare days_in_month INT default (SELECT dayofmonth(LAST_DAY(input_date)));
declare days_over_28 INT default (days_in_month-28);
if days_in_month > 28 then
if (days_over_28 > (dayindex-start_day_idx)) and ((dayindex-start_day_idx) >= 0) then
return 5;
else
return 4;
end if;
else
return 4;
end if;
END//
Eg to test the count of all days in a month:
select
count_days_in_month('2020-02-01',1) 'Sun',
count_days_in_month('2020-02-01',2) 'Mon',
count_days_in_month('2020-02-01',3) 'Tue',
count_days_in_month('2020-02-01',4) 'Wed',
count_days_in_month('2020-02-01',5) 'Thur',
count_days_in_month('2020-02-01',6) 'Fri',
count_days_in_month('2020-02-01',7) 'Sat'
from
dual;//