mysql访问多个数据库实例

import pymysql

# 连接到第一个数据库实例
conn1 = pymysql.connect(host='host1', user='user1', password='password1', db='db1')

# 连接到第二个数据库实例
conn2 = pymysql.connect(host='host2', user='user2', password='password2', db='db2')

# 进行数据库操作
cursor1 = conn1.cursor()
cursor1.execute("SELECT * FROM table1")
result1 = cursor1.fetchall()

cursor2 = conn2.cursor()
cursor2.execute("SELECT * FROM table2")
result2 = cursor2.fetchall()

# 关闭连接
cursor1.close()
cursor2.close()
conn1.close()
conn2.close()

-- 编辑主数据库的配置文件（my.cnf）
[mysqld]
server-id=1
log-bin=mysql-bin
binlog-do-db=db1

-- 重启MySQL服务
sudo systemctl restart mysqld

-- 创建复制用户
CREATE USER 'repl'@'%' IDENTIFIED BY 'password';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';

-- 查看主数据库的状态
SHOW MASTER STATUS;

-- 编辑从数据库的配置文件（my.cnf）
[mysqld]
server-id=2
relay-log=mysql-relay-bin
log-slave-updates=1
read-only=1

-- 重启MySQL服务
sudo systemctl restart mysqld

-- 配置从数据库连接到主数据库
CHANGE MASTER TO
MASTER_HOST='host1',
MASTER_USER='repl',
MASTER_PASSWORD='password',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=107;

-- 启动从数据库的复制功能
START SLAVE;

-- 修改MySQL配置文件（my.cnf）
[mysqld]
wait_timeout=3600

-- 重启MySQL服务
sudo systemctl restart mysqld

from sqlalchemy import create_engine
from sqlalchemy.pool import QueuePool

engine = create_engine('mysql+pymysql://user:password@host/db', poolclass=QueuePool, pool_size=10, max_overflow=20)