如何让Mysql支持emoji（表情）

你的应用在使用emoji么？接下来我将介绍如何让Mysql切换为utf8mb4编码，让其支持emoji表情。

1.备份数据库。

2.升级Mysql版本，Mysql版本号必须大于5.5.3。

3.更改数据库、数据表、表列的编码为utf8mb4_general_ci

# For each database:
ALTER DATABASE database_name CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci;
# For each table:
ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
# For each column:
ALTER TABLE table_name CHANGE column_name column_name VARCHAR(191) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

4.更改Mysql的connection, client, and server character 配置项

编辑my.cnf加入如下内容：

[client]
default-character-set = utf8mb4
[mysql]
default-character-set = utf8mb4
[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_general_ci

重启Mysql，检查编码是否生效。

SHOW VARIABLES WHERE Variable_name LIKE 'character\_set\_%' OR Variable_name LIKE 'collation%';

+--------------------------+--------------------+
| 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               |
| collation_connection     | utf8mb4_general_ci |
| collation_database       | utf8mb4_general_ci |
| collation_server         | utf8mb4_general_ci |
+--------------------------+--------------------+
10 rows in set (0.00 sec)

最后在程序中修改默认的数据库连接编码为utf8mb4