http://mindthelog.com/2014/05/%EA%B5%AC%EA%B8%80-%EC%A0%84%EC%9E%90%EC%83%81%EA%B1%B0%EB%9E%98-%EB%A1%9C%EA%B7%B8%EB%B6%84%EC%84%9D-%EA%B3%BC%EC%A0%95-%EA%B0%9C%EB%85%90/http://mindthelog.com/2014/06/ecommerce-%EC%A0%84%EC%9E%90%EC%83%81%EA%B1%B0%EB%9E%98-
Important Note: Converting from utf8mb4 to utf8 may cause loss of data.It is advisable to take a full database backup, before carrying out the steps below, and inspect your site in full after the changes, to ensure there is no corruption.Since WordPress 4.