※ 쿼리
SELECT DATE_FORMAT('regist_date`, '%Y%m%d') AS date, count(*) AS cnt
FROM data_table
GROUP BY DATE_FORMAT('regist_date`, '%Y%m%d')
ORDER BY date DESC;
※ 실행결과

※ 쿼리
SELECT DATE_FORMAT('regist_date`, '%Y%m%d') AS date, count(*) AS cnt
FROM data_table
GROUP BY DATE_FORMAT('regist_date`, '%Y%m%d')
ORDER BY date DESC;
※ 실행결과