mysql 支持emoji

1.修改my.cnf

[client]
default-character-set = utf8mb4

[mysqld]
collation-server = utf8mb4_unicode_ci
character-set-server = utf8mb4重启mysql，检查字符集是否已经更改，除了character_set_system和character_set_filesystem之外，其他的字符集都需要变成utf8mb4类型。查看编码如下。

mysql> show variables like ‘char%‘;
+--------------------------+------------------------------------------------------+
| Variable_name            | Value                                                |
+--------------------------+------------------------------------------------------+
| character_set_client     | utf8mb4                                              |
| character_set_connection | utf8mb4                                              |
| character_set_database   | utf8mb4                                              |
| character_set_filesystem | binary                                               |
| character_set_results    | utf8mb4                                              |
| character_set_server     | utf8mb4                                              |
| character_set_system     | utf8                                                 |
| character_sets_dir       | /usr/local/Cellar/mysql/5.5.10/share/mysql/charsets/ |
+--------------------------+------------------------------------------------------+

2.为了支持之前用utf8创建的表同样支持emoji，你还需要将之前的表修改未utf8mb4字符集

alter table posts convert to character set utf8mb4 collate utf8mb4_unicode_ci;

3.如果处理完成之后，插入还是失败，那么在db的URL参数上不要加characterEncoding参数。 不加这个参数时，默认值就时autodetect。

4.mysql支持emoji有版本约束，建议mysql升级至5.5，mysql-connetion升级至5.1.30。