Issue with SQL getting Upcoming Birthdays - mysql

Question

Can anyone fix the following SQL code, which gets upcoming birthdays:
SELECT *
FROM personal
WHERE 1 = ( FLOOR( DATEDIFF( DATE_ADD( DATE( NOW( ) ) , INTERVAL :interval DAY ) , dob ) / 365.25 ) ) -
( FLOOR( DATEDIFF( DATE_ADD( DATE( NOW( ) ) , INTERVAL -1 DAY ) , dob ) / 365.25 ) )
ORDER BY MONTH( dob ), DAY( dob )
LIMIT :rangeStart,:limit
It works aside from there is a bug with the ordering if the year rolls over. E.g. your in December checking ahead 1 month, then January birthday will get ordered before December.
I've seen a few posts on here about doing this, but none of them seem to get this part correct. I tried using the following ORDER BY clause, from another post and which seemed to work for someone else, but when I run it I get a syntax error:
ORDER BY ( MONTH(dob) > MONTH(NOW() OR ((MONTH(dob) = MONTH(NOW()) AND DAY(dob) >= DAY(NOW()) DESC, MONTH(dob), DAY(dob)

Answer 1

Updated answer ...
Thought of a cleaner way to accomplish this:
SELECT *
FROM (
SELECT *
,DATE_ADD( MAKEDATE( YEAR( NOW() ), DAYOFYEAR( dob ) )
,INTERVAL IF( DAYOFYEAR( dob ) < DAYOFYEAR( NOW() ), 1, 0 ) YEAR
)
AS next_birthday
FROM personal
) a
WHERE a.next_birthday < DATE_ADD( NOW(), INTERVAL :interval DAY )
ORDER BY a.next_birthday ASC
LIMIT :rangeStart,:limit
Explanation: next_birthday is calculated by taking this year's birthday and adding either 1 or 0 years to it depending on whether or not the birthday has already occurred this year - determined by IF( DAYOFYEAR( dob ) < DAYOFYEAR( NOW() ), 1, 0 ).
See it in action in SQLFiddle at http://sqlfiddle.com/#!9/b6471/1. Play with the number of days to see January after December.
Original answer ...
Add the following to your SELECT:
SELECT *
, CASE WHEN MAKEDATE( YEAR( CURRENT_DATE ), DAYOFYEAR( dob ) ) >= CURRENT_DATE
THEN MAKEDATE( YEAR( CURRENT_DATE ), DAYOFYEAR( dob ) )
ELSE DATE_ADD( MAKEDATE( YEAR( CURRENT_DATE ), DAYOFYEAR( dob ) ), INTERVAL 1 YEAR )
END AS next_birthday
then
ORDER BY next_birthday ASC
Rewriting your original query you get something like:
SELECT a.*
FROM ( SELECT *
, CASE WHEN DAYOFYEAR( dob ) >= DAYOFYEAR( CURRENT_DATE )
THEN MAKEDATE( YEAR( CURRENT_DATE ), DAYOFYEAR( dob ) )
ELSE DATE_ADD( MAKEDATE( YEAR( CURRENT_DATE ), DAYOFYEAR( dob ) ), INTERVAL 1 YEAR )
END AS next_birthday
FROM personal
) a
WHERE a.next_birthday < DATE_ADD( CURRENT_DATE, INTERVAL :interval DAY )
ORDER BY a.next_birthday ASC
LIMIT :rangeStart,:limit

Answer 2

I've now found a solution. For those that would like to know, the final code is:
SELECT *, DATE_ADD( dob, INTERVAL YEAR( FROM_DAYS( DATEDIFF( NOW( ), dob) -1 ) ) + 1 YEAR) AS next_birthday
FROM personal
WHERE 1 = ( FLOOR( DATEDIFF( DATE_ADD( DATE( NOW( ) ) , INTERVAL :interval DAY ) , dob ) / 365.25 ) ) -
( FLOOR( DATEDIFF( DATE_ADD( DATE( NOW( ) ) , INTERVAL -1 DAY ) , dob ) / 365.25 ) )
ORDER BY next_birthday ASC
LIMIT :rangeStart,:limit
I haven't tested it fully, but on simple tests it works.