目前我们在PHP中使用以下命令在应用程序中将字符集设置为UTF-8。
因为这有点开销，所以我们希望将其设置为MySQL中的默认设置。我们可以在/etc/my.cnf或其他位置这样做吗?
SET NAMES 'utf8'
SET CHARACTER SET utf8
我在/etc/my.cnf中寻找了一个默认字符集，但那里没有关于字符集的任何内容。
在这一点上，我做了以下设置MySQL字符集和排序变量为UTF-8:
skip-character-set-client-handshake
character_set_client=utf8
character_set_server=utf8
这是正确的处理方式吗?
要将默认值设置为UTF-8，您需要将以下内容添加到my.cnf/my.ini
[client]
default-character-set=utf8mb4
[mysql]
default-character-set=utf8mb4
[mysqld]
collation-server = utf8mb4_unicode_520_ci
init-connect='SET NAMES utf8mb4'
character-set-server = utf8mb4
如果您想更改现有数据库的字符集，请告诉我…你的问题没有直接说明，所以我不确定这是否是你想要做的。
编辑:我在原始答案中用utf8mb4替换了utf8，因为utf8只是UTF-8的一个子集。MySQL和MariaDB都调用UTF-8 utf8mb4。
指令已更改为character-set-system=utf8
http://dev.mysql.com/doc/refman/5.6/en/charset-configuration.html
《NijaCat》也很接近，但却过于夸张:
要将默认值设置为UTF-8，您需要将以下内容添加到my.cnf
[client]
default-character-set=utf8
[mysqld]
default-character-set = utf8
然后，验证:
mysql> show variables like "%character%";show variables like "%collation%";
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_general_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-----------------+
3 rows in set (0.00 sec)
在MySQL 5.5中，我有my.cnf
[mysqld]
init_connect='SET collation_connection = utf8_unicode_ci'
init_connect='SET NAMES utf8'
character-set-server=utf8
collation-server=utf8_unicode_ci
skip-character-set-client-handshake
结果是
mysql> show variables like "%character%";show variables like "%collation%";
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_unicode_ci |
| collation_database | utf8_unicode_ci |
| collation_server | utf8_unicode_ci |
+----------------------+-----------------+
3 rows in set (0.00 sec)
我还发现，在[mysqld]标题下设置default-character-set = utf8后，MySQL 5.5。x不能在Ubuntu 12.04 (Precise穿山甲)下启动。
在Xubuntu 12.04下，我简单地添加了
[mysqld]
character_set_server = utf8
到 /etc/mysql/my.cnf
结果是
mysql> show variables like "%character%";show variables like "%collation%";
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_general_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-----------------+
3 rows in set (0.00 sec)
也可以看看http://dev.mysql.com/doc/refman/5.6/en/charset-server.html
对于MySQL的最新版本，
default-character-set = utf8
造成问题。我认为这是不可取的。
正如Justin Ball在“升级到MySQL 5.5.12，现在MySQL无法启动，你应该:
Remove that directive and you should be good. Then your configuration file ('/etc/my.cnf' for example) should look like that: [mysqld] collation-server = utf8_unicode_ci init-connect='SET NAMES utf8' character-set-server = utf8 Restart MySQL. For making sure, your MySQL is UTF-8, run the following queries in your MySQL prompt: First query: mysql> show variables like 'char%'; The output should look like: +--------------------------+---------------------------------+ | Variable_name | Value | +--------------------------+---------------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /usr/local/mysql/share/charsets/| +--------------------------+---------------------------------+ Second query: mysql> show variables like 'collation%'; And the query output is: +----------------------+-----------------+ | Variable_name | Value | +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database | utf8_unicode_ci | | collation_server | utf8_unicode_ci | +----------------------+-----------------+
这里列出的所有设置都是正确的，但这里是最优和最充分的解决方案:
[mysqld]
init_connect='SET collation_connection = utf8_unicode_ci'
character-set-server = utf8
collation-server = utf8_unicode_ci
[client]
default-character-set = utf8
将这些文件添加到/etc/mysql/my.cnf.
请注意，由于性能问题，我选择utf8_unicode_ci类型的排序。
结果是:
mysql> SHOW VARIABLES LIKE 'character%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
mysql> SHOW VARIABLES LIKE 'collation%';
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_unicode_ci |
| collation_database | utf8_unicode_ci |
| collation_server | utf8_unicode_ci |
+----------------------+-----------------+
这是当您以非super用户连接时!
例如，SUPER用户和非SUPER用户之间的区别(当然是在utf8_unicode_ci排序的情况下):
SUPER priv用户:
mysql> SHOW VARIABLES LIKE 'collation%';
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_general_ci | <---
| collation_database | utf8_unicode_ci |
| collation_server | utf8_unicode_ci |
+----------------------+-----------------+
非super priv用户:
mysql> SHOW VARIABLES LIKE 'collation%';
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_unicode_ci |
| collation_database | utf8_unicode_ci |
| collation_server | utf8_unicode_ci |
+----------------------+-----------------+
我写了一篇全面的文章(rus)，详细解释了为什么你应该使用一种或另一种选项。所有类型的字符集和排序规则都被考虑:服务器，数据库，连接，表，甚至列。
我希望这篇文章和这篇文章将有助于澄清不清楚的时刻。
更改MySQL字符:
客户端
default-character-set=utf8
mysqld
character_set_server=utf8
我们不应该在mysqld中编写default-character-set=utf8，因为这可能会导致如下错误:
start:任务启动失败
最后:
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
MySQL 5.5，所有你需要的是:
[mysqld]
character_set_client=utf8
character_set_server=utf8
collation_server=utf8_unicode_ci
Collation_server是可选的。
mysql> show variables like 'char%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
在进行配置时，MySQL版本和Linux发行版可能很重要。
但是，[mysqld]部分下的更改是受鼓励的。
我想简单解释一下tomazzlender的回答:
[mysqld]
init_connect='SET collation_connection = utf8_unicode_ci'
init_connect='SET NAMES utf8'
character-set-server=utf8
collation-server=utf8_unicode_ci
skip-character-set-client-handshake
[mysqld]
这将把collation_connection更改为utf8_unicode_ci
init_connect='SET collation_connection = utf8_unicode_ci'
使用集合名称:
init_connect='SET NAMES utf8'
SET NAMES将影响三个字符，即:
character_set_client
character_set_results
character_set_connection
这将设置character_set_database & character_set_server
character-set-server=utf8
这只会影响collation_database和collation_server
collation-server=utf8_unicode_ci
对不起，我不太清楚这是干什么用的。但是我不用这个词:
skip-character-set-client-handshake
MySQL v5.5.3及更高版本:
只在[mysqld]部分中添加三行:
[mysqld]
character-set-server = utf8
collation-server = utf8_unicode_ci
skip-character-set-client-handshake
注意:在这里包含skip-character-set-client-handshake可以避免在[mysqld]中包含init-connect，在[client]和[mysql]部分中包含default-character-set。
如果你在使用MySQL Workbench确认客户端的字符集支持时遇到麻烦，那么请记住以下注意事项:
重要的 MySQL Workbench打开的所有连接都会自动设置客户端字符 设置为utf8。手动更改客户端字符集，例如使用set NAMES .．.，可能导致MySQL Workbench不能正确显示字符。为 有关客户端字符集的其他信息，请参见连接字符集 和排序。
因此，我无法用my.cnf更改覆盖MySQL Workbench的字符集。如。设置名称utf8mb4
在Fedora 21上
$ vi /etc/my.cnf
添加:
[client]
default-character-set=utf8
[mysql]
default-character-set=utf8
[mysqld]
init_connect='SET collation_connection = utf8_unicode_ci'
init_connect='SET NAMES utf8'
character-set-server=utf8
collation-server=utf8_unicode_ci
skip-character-set-client-handshake
保存并退出。
最后记住，用service mysqld restart重启服务mysqld。
如果你对客户端的设置感到困惑，重启mysql服务后conn被重置。试试下面这些步骤(对我很有效):
vi /etc/my.cnf 添加内容:blow和:wq (客户端) character-sets-dir = / usr /地方/ mysql /分享/ mysql /数据集 重启mysql，登录mysql，使用数据库，输入命令状态;，你会发现'client'和'conn'的字符集被设置为'utf8'。
查看参考资料了解更多信息。
注意: My.cnf文件位于/etc/mysql/
在添加这些行之后:
[mysqld]
collation-server = utf8_unicode_ci
init-connect='SET NAMES utf8'
character-set-server = utf8
skip-character-set-client-handshake
[client]
default-character-set = utf8
[mysql]
default-character-set = utf8
不要忘记重启服务器:
sudo service mysql restart
对于utf8mb4_general_ci
[client]
default-character-set=utf8mb4
[mysql]
default-character-set=utf8mb4
[mysqld]
collation-server = utf8mb4_general_ci
init-connect='SET NAMES utf8mb4'
character-set-server = utf8mb4
根据symfony框架文档https://symfony.com/doc/2.6/book/doctrine.html#configuring-the-database
我们建议不要使用MySQL的utf8字符集，因为它没有 支持4字节unicode字符，包含它们的字符串将是 截断。更新的utf8mb4字符集修复了这个问题。
