Question

I have to get those user records whose birthday is uqual to given date. Since the date format of birthday is "Y-d-m" in my database, first I need to convert it to "d-m" format. After that select this field. I use the query something like:

SELECT *, DATE_FORMAT(birthday, '%d-%m') AS birthday_date
FROM users
WHERE birthday_date = '03-06'

but it returns unknown column error:

Unknown column 'birthday_date' in 'where clause'

So how can I solve this problem?

Thanks in advance.

Answer 1

You need to use having 🙂

SELECT *, DATE_FORMAT(birthday, '%d-%m') AS birthday_date
FROM users
HAVING DATE_FORMAT(birthday, '%d-%m') = '03-06'

or

SELECT * FROM(
    SELECT *, DATE_FORMAT(birthday, '%d-%m') AS birthday_date
    FROM users
) a
WHERE a.birthday_date = '03-06'