mysql切换从库

import mysql.connector

def get_database_connection():
    # 默认连接到主库
    config = {
        'user': 'root',
        'password': 'password',
        'host': 'master_host',
        'database': 'mydatabase'
    }
    return mysql.connector.connect(**config)

def switch_to_slave():
    # 切换到从库
    config['host'] = 'slave_host'
    return mysql.connector.connect(**config)

# 使用示例
try:
    conn = get_database_connection()
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM mytable")
    result = cursor.fetchall()
    print(result)
except mysql.connector.Error as err:
    print(f"Error: {err}")
    # 切换到从库
    conn = switch_to_slave()
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM mytable")
    result = cursor.fetchall()
    print(result)
finally:
    cursor.close()
    conn.close()