[add] set charset

Author: BlueDriver

mysql.md

@@ -3,12 +3,13 @@
 ## 常用命令
 1. `desc;` 查看表结构
 2. `show variables like 'char%';`	查看字符集设置
-3. `source file.sql;`	导入数据，要在file.sql目录下进行
-4. centOS下，`etc/my.cfg`，设置MySQL字符集
-5. `service mysqld restart`	重启MySQL
-6. `mysql -u root -p`	登录MySQL
-7. `select version();`	查看MySQL版本（要先登录MySQL）
-8. `status;` 查看MySQL状态（版本、字符集等）
+3. `show charset` 查看支持的字符集
+4. `source file.sql;`	导入数据，要在file.sql目录下进行
+5. centOS下，`etc/my.cfg`，设置MySQL字符集
+6. `service mysqld restart`	重启MySQL
+7. `mysql -u root -p`	登录MySQL
+8. `select version();`	查看MySQL版本（要先登录MySQL）
+9. `status;` 查看MySQL状态（版本、字符集等）
 
 ## 数据备份
 
@@ -48,4 +49,55 @@ mysql -u root -p db < books.sql
 ##  注意事项
 
 1. MySQL在 5.5.3 之后增加了 **utf8mb4** 字符编码，mb4即 most bytes 4。简单说 utf8mb4 是 utf8 的超集并完全兼容utf8，能够用四个字节存储更多的字符。而utf8 是 utf8mb3 的别名。标准的 UTF-8 字符集编码是可以用 1~4 个字节去编码21位字符，但是MySQL其实实现的utf8只是使用3个字节而已， `utf8mb4才是真正意义上的 utf8`，`emoji`表情要用utf8mb4存
-2. 
+
+##  MySQL5.7修改字符集
+
+配置文件位置：
+
+```mysql
+ /etc/mysql/mysql.conf.d/mysqld.cnf
+```
+
+设置为utf8mb4：
+
+```mysqll
+# Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+
+#
+# The MySQL  Server configuration file.
+#
+# For explanations see
+# http://dev.mysql.com/doc/mysql/en/server-system-variables.html
+#------------------------------------------------ add 1
+[client]
+default-character-set=utf8mb4
+#------------------------------------------------ add 2
+
+[mysqld]
+pid-file	= /var/run/mysqld/mysqld.pid
+socket		= /var/run/mysqld/mysqld.sock
+datadir		= /var/lib/mysql
+#log-error	= /var/log/mysql/error.log
+# By default we only accept connections from localhost
+#bind-address	= 127.0.0.1
+# Disabling symbolic-links is recommended to prevent assorted security risks
+symbolic-links=0
+#------------------------------------------------ add 2
+character-set-server=utf8mb4
+#------------------------------------------------ add 2
+```
+
+上面中两处add是要加的内容，加完之后重启MySQL，然后登陆MySQL，执行`status`查看当前状态。