解决办法：CentOS7下修改MySQL数据库字符编码为UTF-8，UTF-8包含全世界所有国家所需要的字符集，是国际编码。
具体操作如下：
1.进入MySQL
[root@tianqi-01 ~]# mysql -uroot -p
Enter password: #输入密码
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 4
Server version: 5.6.35-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql>
2.查看当前MySQL运行状态
mysql> status;
--------------
mysql Ver 14.14 Distrib 5.6.35, for linux-glibc2.5 (x86_64) using EditLine wrapper
Connection id: 4
Current database:
Current user: root@localhost
SSL: Not in use
Current pager: stdout
Using outfile: ''
Using delimiter: ;
Server version: 5.6.35-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
Server characterset: latin1
Db characterset: latin1
Client characterset: utf8
Conn. characterset: utf8
UNIX socket: /tmp/mysql.sock
Uptime: 16 min 19 sec
Threads: 3 Questions: 26 Slow queries: 0 Opens: 82 Flush tables: 1 Open tables: 75 Queries per second avg: 0.026
--------------
mysql>
3.修改MySQL配置文件
[root@tianqi-01 ~]# vim /etc/my.cnf
[client]
default-character-set=utf8
[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci
datadir=/data/mysql
socket=/tmp/mysql.sock
server-id=130
log_bin=aminglinux1
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
#log-error=/var/log/mariadb/mariadb.log
#pid-file=/var/run/mariadb/mariadb.pid
#
# include all files from the config directory
#
#!includedir /etc/my.cnf.d
保存退出
*我的MySQL里面没有[client]字段，自己添加上，在[client]字段下面添加default-character-set=utf8
*在[mysqld]字段下面添加
character-set-server=utf8
collation-server=utf8_general_ci
*保存退出
4.重启MySQL服务
[root@tianqi-01 ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. [ OK ]
Starting MySQL.. [ OK ]
[root@tianqi-01 ~]#
5.查看当前MySQL运行状态
mysql> status;
--------------
mysql Ver 14.14 Distrib 5.6.35, for linux-glibc2.5 (x86_64) using EditLine wrapper
Connection id: 3
Current database:
Current user: root@localhost
SSL: Not in use
Current pager: stdout
Using outfile: ''
Using delimiter: ;
Server version: 5.6.35-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
Server characterset: utf8
Db characterset: utf8
Client characterset: utf8
Conn. characterset: utf8
UNIX socket: /tmp/mysql.sock
Uptime: 49 sec
Threads: 3 Questions: 5 Slow queries: 0 Opens: 70 Flush tables: 1 Open tables: 63 Queries per second avg: 0.102
--------------
mysql>
此时所有编码应该都是UTF-8
参数说明：
haracter_set_client：客户端请求数据的字符集。
character_set_connection：从客户端接收到数据，然后传输的字符集。
character_set_database：默认数据库的字符集，无论默认数据库如何改变，都是这个字符集；如果没有默认数据库，使character_set_server指定的字符集，此参数无需设置。
character_set_filesystem：把操作系统上文件名转化成此字符集，即把character_set_client转换character_set_filesystem，默认binary即可。
character_set_results：结果集的字符集。
character_set_server：数据库服务器的默认字符集。
character_set_system：这个值总是utf8，不需要设置，存储系统元数据的字符集。