通过 Python 连接到 MySQL 我得到了相互矛盾的结果

Question

我正在尝试连接到托管在 Python Anywhere 上的 MySQL 数据库。在下面的示例中 connection.get_server_info() returns 结果是 connection.is_connected() returns False 我不确定为什么。

这是我的代码：

import mysql.connector
import sshtunnel

sshtunnel.SSH_TIMEOUT = 5.0
sshtunnel.TUNNEL_TIMEOUT = 5.0

with sshtunnel.SSHTunnelForwarder(
    ('ssh.pythonanywhere.com'),
    ssh_username='USERNAME', ssh_password='PASSWORD',
    remote_bind_address=('USERNAME.mysql.pythonanywhere-services.com', 3306)
) as tunnel:
    connection = mysql.connector.connect(
        user='USERNAME', password='DB_PASSWORD',
        host='127.0.0.1', port=tunnel.local_bind_port,
        database='USERNAME$default',
    )
db_info = connection.get_server_info()
if connection.is_connected():      
    print('Connected to MySQL DB...version on ', db_info)
else:
    print('Failed to connect.')
print(db_info)
connection.close()

我在 Python Anywhere 上有一个付费帐户，所以 SSH 隧道应该是可能的

Answer 1

这是因为您试图在 SSH 隧道关闭后访问它；当您退出 with 块时，隧道将关闭，因此需要缩进任何使用该连接的内容，以便将其包含在其中。您上面的代码如下所示：

import mysql.connector
import sshtunnel

sshtunnel.SSH_TIMEOUT = 5.0
sshtunnel.TUNNEL_TIMEOUT = 5.0

with sshtunnel.SSHTunnelForwarder(
    ('ssh.pythonanywhere.com'),
    ssh_username='USERNAME', ssh_password='PASSWORD',
    remote_bind_address=('USERNAME.mysql.pythonanywhere-services.com', 3306)
) as tunnel:
    connection = mysql.connector.connect(
        user='USERNAME', password='DB_PASSWORD',
        host='127.0.0.1', port=tunnel.local_bind_port,
        database='USERNAME$default',
    )
    db_info = connection.get_server_info()
    if connection.is_connected():      
        print('Connected to MySQL DB...version on ', db_info)
    else:
        print('Failed to connect.')
    print(db_info)
    connection.close()

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