版本信息

ubuntu版本：16.04.1
mysql-server版本：5.7.23

安裝

先查看一下apt可獲取的mysql版本

ubuntu@VM-0-4-ubuntu:~$ apt search mysql

看到結果裡面有這兩個package，我們安裝mysql-server就可以了，可以看到提供的mysql-server是5.7.23的。

mysql-client/xenial-security,xenial-security,xenial-updates,xenial-updates 5.7.23-0ubuntu0.16.04.1 all
  MySQL database client (metapackage depending on the latest version)

mysql-server/xenial-security,xenial-security,xenial-updates,xenial-updates 5.7.23-0ubuntu0.16.04.1 all
  MySQL database server (metapackage depending on the latest version)

安裝apt提供的mysql

sudo apt install mysql-server

開始安裝，直接選Y就可以

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libaio1 libcgi-fast-perl libcgi-pm-perl libencode-locale-perl
  libevent-core-2.0-5 libfcgi-perl libhtml-parser-perl libhtml-tagset-perl
  libhtml-template-perl libhttp-date-perl libhttp-message-perl libio-html-perl
  liblwp-mediatypes-perl libtimedate-perl liburi-perl mysql-client-5.7
  mysql-client-core-5.7 mysql-common mysql-server-5.7 mysql-server-core-5.7
Suggested packages:
  libdata-dump-perl libipc-sharedcache-perl libwww-perl mailx tinyca
The following NEW packages will be installed:
  libaio1 libcgi-fast-perl libcgi-pm-perl libencode-locale-perl
  libevent-core-2.0-5 libfcgi-perl libhtml-parser-perl libhtml-tagset-perl
  libhtml-template-perl libhttp-date-perl libhttp-message-perl libio-html-perl
  liblwp-mediatypes-perl libtimedate-perl liburi-perl mysql-client-5.7
  mysql-client-core-5.7 mysql-common mysql-server mysql-server-5.7
  mysql-server-core-5.7
0 upgraded, 21 newly installed, 0 to remove and 195 not upgraded.
Need to get 19.4 MB of archives.
After this operation, 162 MB of additional disk space will be used.
Do you want to continue? [Y/n]

安裝的過程中會讓你設置root用戶的密碼,設置一下，一會登錄mysql會用到


檢測一下是否安裝成功

sudo netstat -tap | grep mysql

出現以下內容就是安裝成功了

tcp        0      0 localhost.localdo:mysql *:*                     LISTEN      26647/mysqld

修改字元集

使用root用戶和剛設置的密碼登錄mysql

mysql -u root -p

先看下未修改前的字元集

mysql> show variables like '%char%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

我們通過修改mysql的配置文件my.cnf（是mysql.conf的鏈接文件，直接改mysql.conf也行，沒區別）來修改字元集。
配置文件的位置在/etc/mysql/my.cnf，用vim修改的時候前面要加sudo，因為非root用戶沒有這個文件的寫許可權。

sudo vim /etc/mysql/my.cnf

未修改前的配置文件應該長這個樣子。

#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
#
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

在後面添加以下信息，設置mysql的字元集。

#[client]
#default-character-set=utf8
#影響系統變數character_set_client和character_set_connectioncharacter_set_results，所以[client]那部分設置不用添加
[mysqld]
character-set-server=utf8
#影響系統變數character_set_server和character_set_database，因為這兩個系統變數預設是latin1，所以要添加

修改保存後重啟mysql，記得加sudo，因為非root用戶沒有重啟的許可權。

sudo service mysql restart

然後再看下資料庫的字元集，全改成了utf8。

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/ |
+--------------------------+----------------------------+