mysql utf8改utf8mb4

由于需要用到utf8mb4，之前是utf8现在给改成utf8mb4

查看当前环境

SHOW VARIABLES WHERE Variable_name LIKE 'character\_set\_%' OR Variable_name LIKE 'collation%';
+--------------------------+--------------------+
| Variable_name            | Value              |
+--------------------------+--------------------+
| character_set_client     | latin1             |
| character_set_connection | latin1             |
| character_set_database   | utf8mb4            |
| character_set_filesystem | binary             |
| character_set_results    | latin1             |
| character_set_server     | utf8mb4            |
| character_set_system     | utf8               |
| collation_connection     | latin1_swedish_ci  |
| collation_database       | utf8mb4_general_ci |
| collation_server         | utf8mb4_general_ci |
+--------------------------+--------------------+

打开MySQL的配置文件，将字符集的配置修改成如下：

[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
init_connect='SET NAMES utf8mb4'

修改后

root@localhost:(none)>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 |
+--------------------------+--------------------+

root@localhost:(none)>s;
--------------
mysql  Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (x86_64) using readline 5.1

Connection id:        61
Current database:    
Current user:        root@localhost
SSL:            Not in use
Current pager:        stdout
Using outfile:        ''
Using delimiter:    ;
Server version:        5.5.36-log Source distribution
Protocol version:    10
Connection:        Localhost via UNIX socket
Server characterset:    utf8mb4
Db     characterset:    utf8mb4
Client characterset:    utf8mb4
Conn.  characterset:    utf8mb4
UNIX socket:        /tmp/mysql.sock
Uptime:            3 min 22 sec

修改后发现连接报错

mysql: Character set 'utf8mb4' is not a compiled character set and is not specified in the '/usr/share/mysql/charsets/Index.xml' file

修改/usr/share/mysql/charsets/Index.xml

修改前

<charset name="utf8">
  <family>Unicode</family>
  <description>UTF-8 Unicode</description>
  <alias>utf-8</alias>
  <collation name="utf8_general_ci"     id="33">
   <flag>primary</flag>
   <flag>compiled</flag>
  </collation>
  <collation name="utf8_bin"            id="83">
    <flag>binary</flag>
    <flag>compiled</flag>
  </collation>
</charset>

修改后

<charset name="utf8mb4">
  <family>Unicode</family>
  <description>UTF-8 Unicode</description>
  <alias>utf-8</alias>
  <collation name="utf8_general_ci"     id="33">
   <flag>primary</flag>
   <flag>compiled</flag>
  </collation>
  <collation name="utf8_bin"            id="83">
    <flag>binary</flag>
    <flag>compiled</flag>
  </collation>
</charset>