vi /etc/yum.repos.d/MariaDB.repo

[mariadb]
name = MariaDB-10.3
baseurl=http://142.4.219.197/10.3/centos7-amd64
# alternative: baseurl=http://archive.mariadb.org/mariadb-10.3.14/yum/centos7-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=0

yum install MariaDB-server

service  mariadb  start 
sudo mysql_secure_installation

systemctl start mariadb #启动服务
systemctl enable mariadb #设置开机启动
systemctl restart mariadb #重新启动
systemctl stop mariadb.service #停止MariaDB

yum install mysql-server

sudo rpm -ivh mysql-community-common-5.7.38-1.el7.x86_64.rpm 
sudo rpm -ivh mysql-community-libs-5.7.38-1.el7.x86_64.rpm
sudo rpm -ivh mysql-community-client-5.7.38-1.el7.x86_64.rpm 
sudo rpm -ivh mysql-community-server-5.7.38-1.el7.x86_64.rpm 

sudo systemctl enable mysqld
sudo service mysqld start
sudo grep 'temporary password' /var/log/mysqld.log

mysql  -uroot -p
ALTER USER 'root'@'localhost' IDENTIFIED BY 'root';

mysql>create user ds@localhost identified by '123';
mysql>grant all on *.* to ds@localhost identified by '123';
mysql>grant all privileges on *.* to ds@'%' ;
mysql>grant select on *.* to ds@'hostname' identified by '123' with grant option;
MariaDB [mysql]> select host,user,password from mysql.user;

mysql>flush privileges;

# ubuntu - mysql8
sudo apt install mysql-server
sudo cat /etc/mysql/debian.cnf #密码
mysql -u  debian-sys-maint -p
use mysql;
ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY '123456';
FLUSH PRIVILEGES;

sudo vi /etc/mysql/my.cnf

[mysqld]
bind-address=0.0.0.0

vi /etc/my.cnf   /etc/my.cnf.d/mariadb-server.cnf

server-id = 1           
auto-increment-offset = 1    
auto-increment-increment = 2  
log-bin = mysql-bin     
sync_binlog = 1
binlog_checksum = none
binlog_format = mixed 
slave-skip-errors = all

server-id = 2        
auto-increment-offset = 2    
auto-increment-increment = 2    
log-bin = mysql-bin    
sync_binlog = 1
binlog_checksum = none
binlog_format = mixed 
slave-skip-errors = all

#保存配置文件并重启mysql
service mariadb restart
sudo service mysqld restart

#用mysql控制台登录并授权从库可以读取主库的二进制日志
mysql -u root -p
mysql>grant replication slave,replication client on *.* to root@'192.168.56.108' identified by "root";
mysql>flush privileges;

#用mysql控制台登录并授权从库可以读取主库的二进制日志
mysql -u root -p
mysql>grant replication slave,replication client on *.* to root@'192.168.56.109' identified by "root";

mysql>flush privileges;

#查看下log bin日志和pos值位置，并记录File 和Position的值
mysql> show master status;

change  master to master_host='192.168.56.108',master_user='root',master_password='root',master_log_file='mysql-bin.000001',master_log_pos=373;   
start slave;
show slave status\G;
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes


change  master to master_host='192.168.56.109',master_user='root',master_password='root',master_log_file='mysql-bin.000001',master_log_pos=373;   
start slave;
show slave status\G;
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

#stop slave;
#flush logs;

====
create database test;

use test;

CREATE TABLE IF NOT EXISTS `runoob_tbl`(
`runoob_id` INT UNSIGNED AUTO_INCREMENT,
`runoob_title` VARCHAR(100) NOT NULL,
`runoob_author` VARCHAR(40) NOT NULL,
`submission_date` DATE,
PRIMARY KEY ( `runoob_id` )
)ENGINE=InnoDB DEFAULT CHARSET=utf8;

show tables;

INSERT INTO runoob_tbl
(runoob_title, runoob_author, submission_date)
VALUES
("学习 PHP", "菜鸟教程", NOW());


INSERT INTO runoob_tbl
(runoob_title, runoob_author, submission_date)
VALUES
("JAVA 教程", "RUNOOB.COM", '2016-05-06');


select * from runoob_tbl;

drop table runoob_tbl;
drop database test;

-- 统计MySQL指定数据库中有多少张表
SELECT count(*) TABLES, table_schema FROM information_schema.TABLES
GROUP BY table_schema;
 
-- 统计MySQL指定数据库中表数据量
use ;
select table_name,table_rows 
from information_schema.tables 
where TABLE_SCHEMA = '数据库名称' 
order by table_rows desc;

RENAME DATABASE old_database_name TO new_database_name;