New Characters & Emoji Support in WordPress 4.2
Emoji are natively available on all modern devices including mobile phones. WordPress didn’t support emoji natively. WordPress 4.2 resolved this by adding the native support for emoji. You can now use emojis anywhere on your WordPress site.
The support for Emoji was made possible by the underlying work done to add native support for Chinese, Japanese, Korean characters. WordPress 4.2 will automatically switch your utf-8 database to utf8mb4. This change will also allow musical and mathematical symbols and even hieroglyphs.
While many users may not be as excited about Emoji support, the support for more language characters is a huge improvement for a very large global WordPress user base.
需要 >= MySQL 5.5.3版本、从库也必须是5.5的了、低版本不支持这个字符集、复制报错