Prerequisite: MySQL >= 5.5.3
Character set named utf8 (or utf8mb3) uses a maximum of three bytes per character and contains only BMP characters. In order to have a maximum of four bytes per character, you need to:
- switch charset/collation of all your tables/columns to utf8mb4
- edit your config/database.yml to change the
encoding: utf8
lines toencoding: utf8mb4
(and a recent mysql2 gem?)