我正在尝试在我的 Xubuntu 系统上安装 MySQL。我已经安装它一整天了，但一直遇到问题。我尝试安装和删除它多次，但问题并没有神奇地自行解决。
卸载 mysql-server 后，我输入了下一个命令：
sudo apt-get install mysql-server
我从中得到了下一个输出：
Fri Dec 30, 13:05, ~ $ sudo apt-get install mysql-server
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
mysql-client-5.7 mysql-client-core-5.7 mysql-common mysql-server-5.7
mysql-server-core-5.7
Suggested packages:
mailx tinyca
The following NEW packages will be installed:
mysql-client-5.7 mysql-client-core-5.7 mysql-common mysql-server
mysql-server-5.7 mysql-server-core-5.7
0 upgraded, 6 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/18.1 MB of archives.
After this operation, 160 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Preconfiguring packages ...
Selecting previously unselected package mysql-common.
(Reading database ... 199729 files and directories currently installed.)
Preparing to unpack .../mysql-common_5.7.16-0ubuntu0.16.04.1_all.deb ...
Unpacking mysql-common (5.7.16-0ubuntu0.16.04.1) ...
Selecting previously unselected package mysql-client-core-5.7.
Preparing to unpack .../mysql-client-core-5.7_5.7.16-0ubuntu0.16.04.1_amd64.deb ...
Unpacking mysql-client-core-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Selecting previously unselected package mysql-client-5.7.
Preparing to unpack .../mysql-client-5.7_5.7.16-0ubuntu0.16.04.1_amd64.deb ...
Unpacking mysql-client-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Selecting previously unselected package mysql-server-core-5.7.
Preparing to unpack .../mysql-server-core-5.7_5.7.16-0ubuntu0.16.04.1_amd64.deb ...
Unpacking mysql-server-core-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up mysql-common (5.7.16-0ubuntu0.16.04.1) ...
update-alternatives: using /etc/mysql/my.cnf.fallback to provide /etc/mysql/my.cnf (my.cnf) in auto mode
Selecting previously unselected package mysql-server-5.7.
(Reading database ... 199886 files and directories currently installed.)
Preparing to unpack .../mysql-server-5.7_5.7.16-0ubuntu0.16.04.1_amd64.deb ...
Unpacking mysql-server-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Selecting previously unselected package mysql-server.
Preparing to unpack .../mysql-server_5.7.16-0ubuntu0.16.04.1_all.deb ...
Unpacking mysql-server (5.7.16-0ubuntu0.16.04.1) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu13) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up mysql-client-core-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Setting up mysql-client-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Setting up mysql-server-core-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Setting up mysql-server-5.7 (5.7.16-0ubuntu0.16.04.1) ...
update-alternatives: using /etc/mysql/mysql.cnf to provide /etc/mysql/my.cnf (my.cnf) in auto mode
Renaming removed key_buffer and myisam-recover options (if present)
AppArmor parser error for /etc/apparmor.d/usr.sbin.mysqld in /etc/apparmor.d/usr.sbin.mysqld at line 9: Could not open 'abstractions/mysql'
mysql_upgrade: Got error: 1045: Access denied for user 'debian-sys-maint'@'localhost' (using password: YES) while connecting to the MySQL server
Upgrade process encountered error and will not continue.
mysql_upgrade failed with exit status 11
dpkg: error processing package mysql-server-5.7 (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mysql-server:
mysql-server depends on mysql-server-5.7; however:
Package mysql-server-5.7 is not configured yet.
dpkg: error processing package mysql-server (--configure):
dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
Processing triggers for systemd (229-4ubuntu13) ...
Processing triggers for ureadahead (0.100.0-19) ...
Errors were encountered while processing:
mysql-server-5.7
mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)
如何正确安装 MySQL？