SQL that list all birthdays within the next and previous 14 days - sql

Question

I have a MySQL member table, with a DOB field which stores all members' dates of birth in DATE format (Notice: it has the "Year" part)
I'm trying to find the correct SQL to:
List all birthdays within the next 14 days
and another query to:
List all birthdays within the previous 14 days
Directly comparing the current date by:
(DATEDIFF(DOB, now()) <= 14 and DATEDIFF(DOB, now()) >= 0)
will fetch nothing since the current year and the DOB year is different.
However, transforming the DOB to 'this year' won't work at all, because today could be Jan 1 and the candidate could have a DOB of Dec 31 (or vice versa)
It will be great if you can give a hand to help, many thanks! :)

Answer 1

#Eli had a good response, but hardcoding 351 makes it a little confusing and gets off by 1 during leap years.
This checks if birthday (dob) is within next 14 days. First check is if in same year. Second check is if its say Dec 27, you'll want to include Jan dates too.
With DAYOFYEAR( CONCAT(YEAR(NOW()),'-12-31') ), we are deciding whether to use 365 or 366 based on the current year (for leap year).
SELECT dob
FROM birthdays
WHERE DAYOFYEAR(dob) - DAYOFYEAR(NOW()) BETWEEN 0 AND 14
OR
DAYOFYEAR( CONCAT(YEAR(NOW()),'-12-31') ) - ( DAYOFYEAR(NOW()) - DAYOFYEAR(dob) ) BETWEEN 0 AND 14

Answer 2

Here's the simplest code to get the upcoming birthdays for the next x days and previous x days
this query is also not affected by leap-years
SELECT name, date_of_birty
FROM users
WHERE DATE(CONCAT(YEAR(CURDATE()), RIGHT(date_of_birty, 6)))
BETWEEN
DATE_SUB(CURDATE(), INTERVAL 14 DAY)
AND
DATE_ADD(CURDATE(), INTERVAL 14 DAY)

Answer 3

My first thought was it would be easy to just to use DAYOFYEAR and take the difference, but that actually gets kinda trick near the start/end of a yeay. However:
WHERE
DAYOFYEAR(NOW()) - DAYOFYEAR(dob) BETWEEN 0 AND 14
OR DAYOFYEAR(dob) - DAYOFYEAR(NOW()) > 351
Should work, depending on how much you care about leap years. A "better" answer would probably be to extract the DAY() and MONTH() from the dob and use MAKEDATE() to build a date in the current (or potential past/following) year and compare to that.

Answer 4

Easy,
We can obtain the nearer birthday (ie the birthday of this year) by this code:
dateadd(year,datediff(year,dob,getdate()),DOB)
use this in your compares ! it will work.

Answer 5

There are a number of options, I would first try to transform by number of years between current year and row's year (i.e. Add their age).
Another option is day number within the year (but then you have still to worry about the rollover arithmetic or modulo).

Answer 6

This is my query for the 30 days before check:
select id from users where
((TO_DAYS(concat(DATE_FORMAT(NOW(),'%Y'), '-', DATE_FORMAT(date_of_birth, '%m-%d')))-TO_DAYS(NOW()))>=-30
AND (TO_DAYS(concat(DATE_FORMAT(NOW(),'%Y'), '-', DATE_FORMAT(date_of_birth, '%m-%d')))-TO_DAYS(NOW()))<=0)
OR (TO_DAYS(concat(DATE_FORMAT(NOW(),'%Y'), '-', DATE_FORMAT(date_of_birth, '%m-%d')))-TO_DAYS(NOW()))>=(365-31)
and 30 days after:
select id from users where
((TO_DAYS(NOW())-TO_DAYS(concat(DATE_FORMAT(NOW(),'%Y'), '-', DATE_FORMAT(date_of_birth, '%m-%d'))))>=-31
AND (TO_DAYS(NOW())-TO_DAYS(concat(DATE_FORMAT(NOW(),'%Y'), '-', DATE_FORMAT(date_of_birth, '%m-%d'))))<=0)
OR (TO_DAYS(NOW())-TO_DAYS(concat(DATE_FORMAT(NOW(),'%Y'), '-', DATE_FORMAT(date_of_birth, '%m-%d'))))>=(365-30)

Answer 7

My solution is as follow:
select cm.id from users cm where
date(concat(
year(curdate()) - (year(subdate(curdate(), 14)) < year(curdate())
and month(curdate()) < month(cm.birthday)) + (year(adddate(curdate(), 14)) > year(curdate())
and month(curdate()) > month(cm.birthday)), date_format(cm.birthday, '-%m-%d'))) between subdate(curdate(), 14)
and adddate(curdate(), 14);
It looks like it works fine when the period captures the current and next year or the current and previous year