在MySQL和PHP中按日期排序，并重视今天的日期

I want to make an order by date to get the comments of user, but I want to give the importance to today date

if there's a comment today show it first and make the ordering with date for the rest.

I try to make this but always give me an error in syntax

SELECT *
FROM comment
ORDER BY IF(`DATE_TIME_COMMENT` = CURRENT_DATE())

is there any solution ?

First sort by a CASE returning "something lower", if date_time_comment is equal to current_date() and "something higher" else. Then, second, sort by date_time_comment.

SELECT *
       FROM comment
       ORDER BY CASE date_time_comment
                  WHEN current_date()
                    THEN 0
                  ELSE
                    1
                END,
                date_time_comment;

(Possibly add DESC after date_time_comment in the ORDER BY clause, if you want to have newest comments first.)

If you can't have comments with future date, just order by date

SELECT * FROM comment ORDER BY DATE_TIME_COMMENT DESC

If you can have future date, and want to order first the today date, then comments with other date than today, one way to do this is with a UNION

SELECT * FROM (
    SELECT 1 as order, c.* FROM comment c WHERE DATE_TIME_COMMENT = CURRENT_DATE()
    UNION ALL
    SELECT 2 as order, c.* FROM comment c WHERE DATE_TIME_COMMENT <> CURRENT_DATE()
) order by order asc, DATE_TIME_COMMENT desc

That you get first the today comments, then other comments order by date