数据库修改为utf8mb4

1、查看数据库的编码格式  SHOW VARIABLES Like '%char%'; 

 2、修改配置文件my.cnf ，把下面有utf8的都改为utf8mb4

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
[client]
default-character-set=utf8mb4

[mysql]
default-character-set=utf8mb4

[mysqld]
log-bin=mysql-bin 
binlog-format=ROW 
server_id=1 
max_connections=1000

init_connect='SET collation_connection = utf8mb4_unicode_ci'
init_connect='SET NAMES utf8mb4'
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci
skip-character-set-client-handshake

3、重启数据库

查看编码：

4、改数据库编码和表编码

alter database <数据库名> character set utf8mb4;

alter table  <表名>    CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci; 

5、查看数据表的编码格式

show create table <表名>;