我在Ubuntu 16上运行没有问题的MySQL 5.7实例，但是当我尝试安装任何其他软件包或尝试通过apt-get更新现有软件包时，我收到以下错误：
# apt-get upgrade
Setting up mysql-server-5.7 (5.7.20-0ubuntu0.16.04.1) ...
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
mysql_upgrade: [ERROR] 1146: Table 'mysql.plugin' doesn't exist
mysql_upgrade failed with exit status 5
dpkg: error processing package mysql-server-5.7 (--configure):
subprocess installed post-installation script returned error exit status 1
No apport report written because the error message indicates its a followup error from a previous failure.
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
Errors were encountered while processing:
mysql-server-5.7
mysql-server
如果我运行mysqlcheck，看起来某些系统表存在，但其他系统表缺失：
mysql.columns_priv OK
mysql.db OK
mysql.engine_cost
Error : Table 'mysql.engine_cost' doesn't exist
status : Operation failed
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.gtid_executed
Error : Table 'mysql.gtid_executed' doesn't exist
status : Operation failed
mysql.help_category
Error : Table 'mysql.help_category' doesn't exist
status : Operation failed
mysql.help_keyword
Error : Table 'mysql.help_keyword' doesn't exist
status : Operation failed
mysql.help_relation
Error : Table 'mysql.help_relation' doesn't exist
status : Operation failed
mysql.help_topic
Error : Table 'mysql.help_topic' doesn't exist
status : Operation failed
mysql.innodb_index_stats
Error : Table 'mysql.innodb_index_stats' doesn't exist
status : Operation failed
mysql.innodb_table_stats
Error : Table 'mysql.innodb_table_stats' doesn't exist
status : Operation failed
mysql.ndb_binlog_index OK
mysql.plugin
Error : Table 'mysql.plugin' doesn't exist
status : Operation failed
mysql.proc OK
mysql.procs_priv OK
mysql.proxies_priv OK
mysql.server_cost
Error : Table 'mysql.server_cost' doesn't exist
status : Operation failed
mysql.servers
Error : Table 'mysql.servers' doesn't exist
status : Operation failed
mysql.slave_master_info
Error : Table 'mysql.slave_master_info' doesn't exist
status : Operation failed
mysql.slave_relay_log_info
Error : Table 'mysql.slave_relay_log_info' doesn't exist
status : Operation failed
mysql.slave_worker_info
Error : Table 'mysql.slave_worker_info' doesn't exist
status : Operation failed
mysql.slow_log OK
mysql.tables_priv OK
mysql.time_zone
Error : Table 'mysql.time_zone' doesn't exist
status : Operation failed
mysql.time_zone_leap_second
Error : Table 'mysql.time_zone_leap_second' doesn't exist
status : Operation failed
mysql.time_zone_name
Error : Table 'mysql.time_zone_name' doesn't exist
status : Operation failed
mysql.time_zone_transition
Error : Table 'mysql.time_zone_transition' doesn't exist
status : Operation failed
mysql.time_zone_transition_type
Error : Table 'mysql.time_zone_transition_type' doesn't exist
status : Operation failed
mysql.user OK
sys.sys_config
Error : Table 'sys.sys_config' doesn't exist
status : Operation failed
但是，数据库正在正常运行，如果我手动检查SQL，则表示表存在。
mysql> SHOW TABLES;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| engine_cost |
| event |
| func |
| general_log |
| gtid_executed |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| server_cost |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
我使用innodb_file_per_table=1设置，/var/lib/mysql目录的所有者已正确设置为mysql用户。
我想在不转储现有数据的情况下解决此问题，但我的想法已经不多了。
答案 0 :(得分：3)
最后解决问题的唯一方法是清除并重新安装mysql库，备份数据库并在所有过程之后恢复它：
# Backup database
time mysqldump -u root -p database > /var/backups/restore_backup.sql
# Backup config and data
mv /var/lib/mysql /tmp/backups/mysql-lib.bak
cp /etc/mysql/my.cnf /tmp/backups/my.cnf.bak
# Purge library
sudo apt-get remove --purge mysql-server mysql-client mysql-common
sudo apt-get autoremove
sudo apt-get autoclean
# Reinstall
sudo apt-get update
sudo apt-get install mysql-server
# Restore config
cp /tmp/backups/my.cnf.bak /etc/mysql/my.cnf
sudo service mysql restart
# Create database
mysql -u root -p
mysql> CREATE DATABASE database;
# Restore backup
time mysql -u root -p database < /var/backups/restore_backup.sql
答案 1 :(得分：3)
我今天遇到了同样的问题，我设法解决了它没有备份 - 重新安装 - 恢复步骤。 （虽然我有备份，每个人都应该！）
在我的情况下，plugin.ibd目录中有一个/var/lib/mysql/mysql/文件，其他缺少的表也有文件，但可能由于某种原因它们不完整。
我做了以下事情：
mysql.plugin表的文件移动到另一个目录，例如：mv /var/lib/mysql/mysql/plugin.* /other/place/ apt-get upgrade -y看看会发生什么。升级脚本正确地重新创建了mysql.plugin表，并抱怨另一个表。我所做的所有步骤，当然是根本原因：
cd /var/lib/mysql/mysql
mkdir temp
mv engine_cost.* temp/
mv gtid_executed.* temp/
mv help_category.* temp/
mv help_keyword.* temp/
mv help_relation.* temp/
mv help_topic.* temp/
mv innodb_index_stats.* temp/
mv innodb_table_stats.* temp/
mv plugin.* temp/
mv server_cost.* temp/
mv servers.* temp/
mv slave_master_info.* temp/
mv slave_relay_log_info.* temp/
mv slave_worker_info.* temp/
mv time_zone.* temp/
mv time_zone_leap_second.* temp/
mv time_zone_name.* temp/
mv time_zone_transition.* temp/
mv time_zone_transition_type.* temp/
apt-get upgrade -y
我希望它有所帮助。