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  • 第二十二章 Centos7下 Mysql 8.0.24 二进制安装

    一、需求

    公司由于安装jira服务,mariadb数据库已不能满足jira的使用,因此需安装新的mysql8.0,迁移mariadb的数据来保证jira的正常安装。
    

    二、准备工作

    #关闭防火墙
    [root@dxg-ml ~]# systemctl stop firewalld.service
    

    三、安装依赖

    #MySQL依赖于libaio库
    [root@dxg-ml ~]# yum search libaio
    [root@dxg-ml ~]# yum install libaio -y
    

    四、下载Mysql新版本

    [root@dxg-ml ~]# cd /data/software
    [root@dxg-ml software]# wget https://downloads.mysql.com/archives/get/p/23/file/mysql-8.0.24-linux-glibc2.12-x86_64.tar.xz
    

    五、新建用户和用户组

    不指定用户组时,默认生成一个同名用户组并加入 -r,指定为系统用户 -s,指定登录shell
    [root@dxg-ml software]# groupadd mysql
    [root@dxg-ml software]# useradd -r -g mysql -s /bin/false mysql
    

    六、解压Mysql安装包

    #解压安装包到/usr/local目录下
    [root@dxg-ml software]# tar -xvf mysql-8.0.24-linux-glibc2.12-x86_64.tar.xz  -C /usr/local
    
    #进入/usr/local目录
    [root@dxg-ml software]# cd /usr/local/
    
    #查看安装包
    [root@dxg-ml local]# ll
    总用量 8
    drwxr-xr-x  9 root root  129 6月   9 17:33 mysql-8.0.24-linux-glibc2.12-x86_64
    
    #重命名
    [root@dxg-ml local]# mv mysql-8.0.24-linux-glibc2.12-x86_64  mysql
    

    七、新建Mysql存放目录

    #Mysql配置文件目录
    [root@dxg-ml local]# mkdir /usr/local/mysql/etc -p
    
    #Mysql数据目录
    [root@dxg-ml software]# mkdir /usr/local/mysql/data -p
    ps:数据目录不需要建立,配置文件指定时会自动创建数据目录。
    
    #Mysql日志目录
    [root@dxg-ml local]# mkdir /usr/local/mysql/log -p
    
    #授权目录用户
    [root@dxg-ml data]# chown -R mysql:mysql /usr/local/mysql
    

    八、配置mysql配置文件

    [root@dxg-ml bin]# cd /usr/local/mysql/etc/
    
    [root@dxg-ml etc]# cat my.cnf
    [client]
    port    = 13306
    socket = /usr/local/mysql/data/mysql.sock
    
    [mysql]
    prompt="u@h R:m:s [d]> "
    no-auto-rehash
    
    [mysqld]
    user    = mysql
    port    = 13306
    admin_address = 127.0.0.1
    basedir = /usr/local/mysql
    datadir = /usr/local/mysql/data
    socket    = /usr/local/mysql/data/mysql.sock
    pid-file = /usr/local/mysql/data/mysqld.pid
    character-set-server = utf8mb4
    skip_name_resolve = 1
    #这个就是用之前的身份认证插件
    default-authentication-plugin = mysql_native_password
    #保证日志的时间正确
    log_timestamps = SYSTEM
    
    #replicate-wild-ignore-table=mysql.%
    replicate-wild-ignore-table=test.%
    replicate-wild-ignore-table=information_schema.%
    
    # Two-Master configure
    #server-1
    #auto-increment-offset = 1
    #auto-increment-increment = 2
    
    #server-2
    #auto-increment-offset = 2
    #auto-increment-increment = 2
    
    
    # semi sync replication settings #
    #plugin_dir = /usr/local/mysql/lib/mysql/plugin
    #plugin_load = "validate_password.so;rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"
    plugin_dir =/usr/local/mysql/lib/plugin #官方版本的路径
    plugin_load = "rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so" #官方版本的路径
    
    slave_parallel_workers = 4
    slave_parallel_type = LOGICAL_CLOCK
    
    open_files_limit    = 65535
    back_log = 1024
    max_connections = 1024
    max_connect_errors = 1000000
    table_open_cache = 1024
    table_definition_cache = 1024
    table_open_cache_instances = 64
    thread_stack = 512K
    external-locking = FALSE
    max_allowed_packet = 32M
    sort_buffer_size = 4M
    join_buffer_size = 4M
    thread_cache_size = 1536
    interactive_timeout = 600
    wait_timeout = 600
    tmp_table_size = 32M
    max_heap_table_size = 32M
    slow_query_log = 1
    log_timestamps = SYSTEM
    slow_query_log_file = /usr/local/mysql/log/slow.log
    log-error = /usr/local/mysql/log/error.log
    long_query_time = 0.1
    log_queries_not_using_indexes =1
    log_throttle_queries_not_using_indexes = 60
    min_examined_row_limit = 100
    log_slow_admin_statements = 1
    log_slow_slave_statements = 1
    server-id = 3306
    log-bin = mysql-bin
    sync_binlog = 1
    binlog_cache_size = 4M
    max_binlog_cache_size = 2G
    max_binlog_size = 1G
    binlog_expire_logs_seconds=2592000
    master_info_repository = TABLE
    relay_log_info_repository = TABLE
    gtid_mode = on
    enforce_gtid_consistency = 1
    log_slave_updates
    slave-rows-search-algorithms = 'INDEX_SCAN,HASH_SCAN'
    binlog_format = row
    binlog_row_image=FULL
    binlog_checksum = 1
    relay_log_recovery = 1
    relay-log-purge = 1
    key_buffer_size = 32M
    read_buffer_size = 8M
    read_rnd_buffer_size = 4M
    bulk_insert_buffer_size = 64M
    myisam_sort_buffer_size = 128M
    myisam_max_sort_file_size = 10G
    myisam_repair_threads = 1
    lock_wait_timeout = 3600
    explicit_defaults_for_timestamp = 1
    innodb_thread_concurrency = 0
    innodb_sync_spin_loops = 100
    innodb_spin_wait_delay = 30
    
    #transaction_isolation = REPEATABLE-READ
    transaction_isolation = READ-COMMITTED
    #innodb_additional_mem_pool_size = 16M
    innodb_buffer_pool_size = 2867M
    innodb_buffer_pool_instances = 4
    innodb_buffer_pool_load_at_startup = 1
    innodb_buffer_pool_dump_at_shutdown = 1
    innodb_data_file_path = ibdata1:1G:autoextend
    innodb_flush_log_at_trx_commit = 1
    innodb_log_buffer_size = 32M
    innodb_log_file_size = 2G
    innodb_log_files_in_group = 3
    innodb_max_undo_log_size = 4G
    # innodb_undo_directory = /usr/local/mysql/log/undolog
    innodb_undo_tablespaces = 95
    
    # 根据您的服务器IOPS能力适当调整
    # 一般配普通SSD盘的话,可以调整到 10000 - 20000
    # 配置高端PCIe SSD卡的话,则可以调整的更高,比如 50000 - 80000
    innodb_io_capacity = 4000
    innodb_io_capacity_max = 8000
    innodb_flush_sync = 0
    innodb_flush_neighbors = 0
    innodb_write_io_threads = 8
    innodb_read_io_threads = 8
    innodb_purge_threads = 4
    innodb_page_cleaners = 4
    innodb_open_files = 65535
    innodb_max_dirty_pages_pct = 50
    innodb_flush_method = O_DIRECT
    innodb_lru_scan_depth = 4000
    innodb_checksum_algorithm = crc32
    innodb_lock_wait_timeout = 10
    innodb_rollback_on_timeout = 1
    innodb_print_all_deadlocks = 1
    innodb_file_per_table = 1
    innodb_online_alter_log_max_size = 4G
    innodb_stats_on_metadata = 0
    
    # some var for MySQL 8
    log_error_verbosity = 3
    innodb_print_ddl_logs = 1
    binlog_expire_logs_seconds = 2592000
    #innodb_dedicated_server = 0
    
    innodb_status_file = 1
    # 注意: 开启 innodb_status_output & innodb_status_output_locks 后, 可能会导致log-error文件增长较快
    innodb_status_output = 0
    innodb_status_output_locks = 0
    
    #performance_schema
    performance_schema = 1
    performance_schema_instrument = '%memory%=on'
    performance_schema_instrument = '%lock%=on'
    
    #innodb monitor
    innodb_monitor_enable="module_innodb"
    innodb_monitor_enable="module_server"
    innodb_monitor_enable="module_dml"
    innodb_monitor_enable="module_ddl"
    innodb_monitor_enable="module_trx"
    innodb_monitor_enable="module_os"
    innodb_monitor_enable="module_purge"
    innodb_monitor_enable="module_log"
    innodb_monitor_enable="module_lock"
    innodb_monitor_enable="module_buffer"
    innodb_monitor_enable="module_index"
    innodb_monitor_enable="module_ibuf_system"
    innodb_monitor_enable="module_buffer_page"
    innodb_monitor_enable="module_adaptive_hash"
    #validate_password_policy=LOW
    
    [mysqldump]
    quick
    max_allowed_packet = 32M
    
    [mysqld_safe]
    #malloc-lib=/usr/local/mysql/lib/jmalloc.so
    nice=-19
    open-files-limit=65535
    

    九、初始化数据库

    [root@dxg-ml local]# cd /usr/local/mysql/bin/
    
    [root@dxg-ml bin]# ./mysqld --defaults-file=/usr/local/mysql/etc/my.cnf --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data
    2021-06-09T18:04:26.063193+08:00 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
    2021-06-09T18:04:36.855062+08:00 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
    2021-06-09T18:04:55.736783+08:00 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: gop;#_4qnSgq
    

    十、启动数据库

    1.命令行界面启动

    #1.进入mysql配置目录
    [root@dxg-ml local]# cd /usr/local/mysql/bin/
    
    #2.命令行启动mysql服务
    [root@dxg-ml bin]# ./mysqld_safe --defaults-file=/usr/local/mysql/etc/my.cnf &
    
    #3.验证服务
    [root@dxg-ml bin]# ps -ef |grep 13306
    root       694 25542  0 18:54 pts/0    00:00:00 grep --color=auto 13306
    mysql    29542 27905  0 18:31 pts/0    00:00:05 /usr/local/mysql/bin/mysqld --defaults-file=/usr/local/mysql/etc/my.cnf --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/usr/local/mysql/log/error.log --open-files-limit=65535 --pid-file=/usr/local/mysql/data/mysqld.pid --socket=/usr/local/mysql/data/mysql.sock --port=13306
    
    [root@dxg-ml bin]# netstat  -lntp |grep 13306
    tcp6       0      0 :::13306                :::*                    LISTEN      29542/mysqld
    

    2.配置init启动

    #1.拷贝mysql配置文件到init目录下
    [root@dxg-ml bin]# cp /usr/local/mysql/support-files/mysql.server  /etc/init.d/mysqld
    
    #2.启动mysql
    [root@dxg-ml bin]# /etc/init.d/mysqld start
    Starting MySQL.. SUCCESS!
    
    #3.验证服务状态
    [root@dxg-ml bin]# ps -ef |grep 13306
    root       694 25542  0 18:54 pts/0    00:00:00 grep --color=auto 13306
    mysql    29542 27905  0 18:31 pts/0    00:00:05 /usr/local/mysql/bin/mysqld --defaults-file=/usr/local/mysql/etc/my.cnf --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/usr/local/mysql/log/error.log --open-files-limit=65535 --pid-file=/usr/local/mysql/data/mysqld.pid --socket=/usr/local/mysql/data/mysql.sock --port=13306
    
    [root@dxg-ml bin]# netstat  -lntp |grep 13306
    tcp6       0      0 :::13306                :::*                    LISTEN      29542/mysqld
    

    3.配置system启动

    #1.配置system启动
    [root@dxg-ml bin]# vim /usr/lib/systemd/system/mysqld.service
    [Unit]
    Description=MySQL Server
    Documentation=man:mysqld(8)
    Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html
    After=network.target
    After=syslog.target
    
    [Install]
    WantedBy=multi-user.target
    
    [Service]
    User=mysql
    Group=mysql
    ExecStart=/usr/local/mysql/bin/mysqld_safe --defaults-file=/usr/local/mysql/etc/my.cnf
    LimitNOFILE = 5000
    #Restart=on-failure
    #RestartPreventExitStatus=1
    #PrivateTmp=false
    
    #2.重新加载启动文件列表
    [root@dxg-ml bin]# systemctl daemon-reload
    
    ps:服务用哪种方式启动就需要用哪种方式去停止,错的启动或者停止服务方式会造成不可解决的错误。
    #3.停止init进程
    [root@dxg-ml bin]# /etc/init.d/mysqld stop
    
    #4.启动mysql服务
    [root@dxg-ml bin]# systemctl start mysqld.service 
    
    #5.查看服务状态
    [root@dxg-ml bin]# systemctl status mysqld.service
    
    [root@dxg-ml bin]# ps -ef |grep 13306
    root       694 25542  0 18:54 pts/0    00:00:00 grep --color=auto 13306
    mysql    29542 27905  0 18:31 pts/0    00:00:05 /usr/local/mysql/bin/mysqld --defaults-file=/usr/local/mysql/etc/my.cnf --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/usr/local/mysql/log/error.log --open-files-limit=65535 --pid-file=/usr/local/mysql/data/mysqld.pid --socket=/usr/local/mysql/data/mysql.sock --port=13306
    
    [root@dxg-ml bin]# netstat  -lntp |grep 13306
    tcp6       0      0 :::13306                :::*                    LISTEN      29542/mysqld
    

    十一、配置环境变量

    #配置环境变量
    [root@dxg-ml bin]# vim /etc/profile.d/mysqld.sh
    PATH=$PATH:$HOME/bin:/usr/local/mysql/bin
    
    #重载环境变量
    [root@dxg-ml bin]#source /etc/profile.d/mysqld.sh
    

    十二、登录数据库

    1.首次登录数据库

    #登录数据库
    [root@dxg-ml bin]# /usr/local/mysql/bin/mysql --socket=/usr/local/mysql/data/mysql.sock
    Welcome to the MySQL monitor.  Commands end with ; or g.
    Your MySQL connection id is 7
    Server version: 8.0.24 MySQL Community Server - GPL
    
    Copyright (c) 2000, 2021, Oracle and/or its affiliates.
    
    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.常用命令登录数据库

    #登录并配置远程登录
    [root@dxg-ml bin]# mysql -P 13306 -u root -p
    Enter password:
    Welcome to the MySQL monitor.  Commands end with ; or g.
    Your MySQL connection id is 8
    Server version: 8.0.24
    
    Copyright (c) 2000, 2021, Oracle and/or its affiliates.
    
    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.
    
    root@localhost 18:35:  [(none)]>
    
    #查看数据库提示你必须重置你的密码
    root@localhost 18:36:  [(none)]> show databases;
    ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
    
    #修改数据库密码
    root@localhost 18:36:  [(none)]> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root';
    Query OK, 0 rows affected (0.10 sec)
    
    #再次查看数据库
    root@localhost 18:38:  [(none)]> show databases;
    +--------------------+
    | Database           |
    +--------------------+
    | information_schema |
    | mysql              |
    | performance_schema |
    | sys                |
    +--------------------+
    4 rows in set (0.09 sec)
    
    #使用数据库
    root@localhost 18:38:  [(none)]> use mysql;
    Database changed
    
    #这里就可以看到root@localhost这里的密码已经是mysql_native_password方式了
    root@localhost 18:39:  [mysql]> select host, user, authentication_string, plugin from user;
    +-----------+------------------+------------------------------------------------------------------------+-----------------------+
    | host      | user             | authentication_string                                                  | plugin                |
    +-----------+------------------+------------------------------------------------------------------------+-----------------------+
    | localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
    | localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
    | localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
    | localhost | root             | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B                              | mysql_native_password |
    +-----------+------------------+------------------------------------------------------------------------+-----------------------+
    4 rows in set (0.00 sec)
    
    #创建一个远程用户登录
    root@localhost 18:42:  [mysql]> create user 'root'@'%' identified by 'root';
    Query OK, 0 rows affected (0.24 sec)
    
    root@localhost 18:43:  [mysql]> grant all privileges on *.* to 'root'@'%' with grant option;
    Query OK, 0 rows affected (0.06 sec)
    
    root@localhost 18:44:  [mysql]> select host, user, authentication_string, plugin from user;
    +-----------+------------------+------------------------------------------------------------------------+-----------------------+
    | host      | user             | authentication_string                                                  | plugin                |
    +-----------+------------------+------------------------------------------------------------------------+-----------------------+
    | %         | root             | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B                              | mysql_native_password |
    | localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
    | localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
    | localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
    | localhost | root             | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B                              | mysql_native_password |
    +-----------+------------------+------------------------------------------------------------------------+-----------------------+
    5 rows in set (0.00 sec)
    
    #退出数据库
    root@localhost 18:44:  [mysql]> quit
    Bye
    

    十三、迁移数据库目录

    1.背景

    因mysql 8.0 安装在系统盘目录,长久会导致磁盘空间不足,因此需要迁移数据库相关目录
    

    2.停止数据库

    #1.查看数据库进程
    [root@dxg-ml mysql]# ps -ef |grep 13306
    root     22254 17463  0 10:01 pts/1    00:00:00 grep --color=auto 13306
    mysql    29542     1  0 6月09 ?       00:02:22 /usr/local/mysql/bin/mysqld --defaults-file=/usr/local/mysql/etc/my.cnf --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/usr/local/mysql/log/error.log --open-files-limit=65535 --pid-file=/usr/local/mysql/data/mysqld.pid --socket=/usr/local/mysql/data/mysql.sock --port=13306
    您在 /var/spool/mail/root 中有邮件
    
    #杀死数据库进程
    [root@dxg-ml mysql]# kill -9 29542
    
    #3.查看数据库进程
    [root@dxg-ml mysql]# ps -ef |grep 13306
    root     22281 17463  0 10:01 pts/1    00:00:00 grep --color=auto 13306
    

    3.新建数据库存放目录

    [root@dxg-ml ~]# mkdir /data/mysql-8.0.24
    [root@dxg-ml ~]# cd /data/mysql-8.0.24/
    

    4.移动相关数据目录

    [root@dxg-ml mysql-8.0.24]# mv /usr/local/mysql/data ./
    [root@dxg-ml mysql-8.0.24]# mv /usr/local/mysql/etc ./
    [root@dxg-ml mysql-8.0.24]# mv /usr/local/mysql/log ./
    

    5.配置数据库软连接

    [root@dxg-ml mysql-8.0.24]# ln -s /data/mysql-8.0.24/data /usr/local/mysql/
    [root@dxg-ml mysql-8.0.24]# ln -s /data/mysql-8.0.24/log /usr/local/mysql/
    [root@dxg-ml mysql-8.0.24]# ln -s /data/mysql-8.0.24/etc /usr/local/mysql/
    
    #查看相关软连接
    [root@dxg-ml mysql-8.0.24]# cd /usr/local/mysql/
    [root@dxg-ml mysql]# ll
    总用量 284
    drwxr-xr-x  2 mysql mysql   4096 6月   9 19:06 bin
    lrwxrwxrwx  1 root  root      23 6月  10 09:54 data -> /data/mysql-8.0.24/data
    drwxr-xr-x  2 mysql mysql     55 3月  26 03:42 docs
    lrwxrwxrwx  1 root  root      23 6月  10 09:54 etc -> /data/mysql-8.0.24/etc
    drwxr-xr-x  3 mysql mysql    282 3月  26 03:42 include
    drwxr-xr-x  6 mysql mysql    201 3月  26 03:42 lib
    -rw-r--r--  1 mysql mysql 274942 3月  22 16:44 LICENSE
    lrwxrwxrwx  1 root  root      22 6月  10 09:54 log -> /data/mysql-8.0.24/log
    drwxr-xr-x  4 mysql mysql     30 3月  26 03:42 man
    -rw-r--r--  1 mysql mysql    666 3月  22 16:44 README
    drwxr-xr-x 28 mysql mysql   4096 3月  26 03:42 share
    drwxr-xr-x  2 mysql mysql     77 3月  26 03:42 support-files
    
    

    6.重启服务

    #1.重启服务
    [root@dxg-ml mysql]# systemctl  restart  mysqld.service
    
    #2.查看服务状态
    [root@dxg-ml mysql]# systemctl  status mysqld.service
    ● mysqld.service - MySQL Server
       Loaded: loaded (/usr/lib/systemd/system/mysqld.service; disabled; vendor preset: disabled)
       Active: active (running) since 四 2021-06-10 10:01:40 CST; 5s ago
         Docs: man:mysqld(8)
               http://dev.mysql.com/doc/refman/en/using-systemd.html
     Main PID: 22307 (mysqld_safe)
       CGroup: /system.slice/mysqld.service
               ├─22307 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/usr/local/mysql/etc/my.cnf
               └─23949 /usr/local/mysql/bin/mysqld --defaults-file=/usr/local/mysql/etc/my.cnf --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --log-error=/usr/loca...
    
    6月 10 10:01:40 dxg-ml systemd[1]: Started MySQL Server.
    6月 10 10:01:40 dxg-ml systemd[1]: Starting MySQL Server...
    6月 10 10:01:41 dxg-ml mysqld_safe[22307]: 2021-06-10T02:01:41.972907Z mysqld_safe Logging to '/usr/local/mysql/log/error.log'.
    6月 10 10:01:41 dxg-ml mysqld_safe[22307]: 2021-06-10T02:01:41.991896Z mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data
    

    7.登录数据库

    [root@dxg-ml mysql]# mysql -P 13306 -u root -p
    Enter password:
    Welcome to the MySQL monitor.  Commands end with ; or g.
    Your MySQL connection id is 8
    Server version: 8.0.24 MySQL Community Server - GPL
    
    Copyright (c) 2000, 2021, Oracle and/or its affiliates.
    
    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.
    
    root@localhost 10:02:  [(none)]>
    root@localhost 10:02:  [(none)]>
    root@localhost 10:02:  [(none)]>
    root@localhost 10:02:  [(none)]> show databases;
    +--------------------+
    | Database           |
    +--------------------+
    | information_schema |
    | mysql              |
    | performance_schema |
    | sys                |
    +--------------------+
    4 rows in set (0.18 sec)
    
    root@localhost 10:02:  [(none)]>
    root@localhost 10:02:  [(none)]>
    root@localhost 10:02:  [(none)]>
    root@localhost 10:02:  [(none)]> quit
    Bye
    
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  • 原文地址:https://www.cnblogs.com/jhno1/p/15324336.html
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