MySQL utf8mb4 字符集：支持 emoji 表情符号
㈠ 序言
为了应对无线互联网的机遇和挑战、避免 emoji 表情符号带来的问题、
涉及无线相关的 MySQL 数据库建议都提前采用 utf8mb4 字符集
这必须要作为移动互联网行业的一个技术选型的要点
㈡ 限制
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
㈢ 简要步骤
以下是一个未升级到 5.5.3 的配置步骤：
① 备份数据库
② 升级 MySQL Server 到 v5.5.3+
③ 修改 database、table和column字符集
For each database:ALTER DATABASE database_name CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;# For each table:ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;# For each column:ALTER TABLE table_name CHANGE column_name column_name VARCHAR(191) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;# (Don’t blindly copy-paste this! The exact statement depends on the column type, maximum length, and other properties. The above line is just an example for a `VARCHAR` column.)
④ 修改 my.cnf
[client]
default-character-set = utf8mb4
[mysql]
default-character-set = utf8mb4
[mysqld]
character-set-client-handshake = FALSE
character-set-server =
utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect=‘SET NAMES
utf8mb4‘
⑤ 重启 MySQL Server、检查字符集
mysql> 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_unicode_ci |
| collation_database |
utf8mb4_unicode_ci |
| collation_server |
utf8mb4_unicode_ci
|
+--------------------------+--------------------+
rows in set
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