mysql 5.5 数据库 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_ciinit_connect=‘SET NAMES utf8mb4‘

修改后

[email protected]:(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 |
+--------------------------+--------------------+

[email protected]:(none)>\s;--------------mysql  Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (x86_64) using readline 5.1

Connection id:        61Current database:    Current user:        [email protected]SSL:            Not in useCurrent pager:        stdoutUsing outfile:        ‘‘Using delimiter:    ;Server version:        5.5.36-log Source distributionProtocol version:    10Connection:        Localhost via UNIX socketServer characterset:    utf8mb4Db     characterset:    utf8mb4Client characterset:    utf8mb4Conn.  characterset:    utf8mb4UNIX socket:        /tmp/mysql.sockUptime:            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>

原文地址：https://www.cnblogs.com/DataArt/p/10092238.html