SSH隧道连接PythonAnywhere MySQL至Tableau失败：端口与权限问题

Let's break down why your Python code works but Tableau is throwing that access denied error, and fix it step by step.

First: Fix the MySQL Username Format (The Most Common Culprit) #

PythonAnywhere uses a specific naming convention for MySQL users: it's your_pythonanywhere_username$your_db_username, not just myusername. For example, if your PythonAnywhere username is jonathanbechtel and your DB user is the default root, your full MySQL username is jonathanbechtel$root.

That's likely why you're seeing Access denied for user 'myusername'@'localhost'—you're probably entering just the short username in Tableau, while your Python code is using the full formatted one (check your info['username'] value, I bet it's the full string).

Second: Ensure Your SSH Tunnel is Properly Configured and Active #

For Git Bash: #

Your tunnel command is correct, but a few things to check:

• Keep the SSH session open: The tunnel only exists while the Git Bash window is running. If you close it, the connection drops.
• Avoid port conflicts: If you have a local MySQL server running on 3306, switch to another port like 3307 to avoid clashes:

  ssh -L 3307:jonathanbechtel.mysql.pythonanywhere-services.com:3306 jonathanbechtel@ssh.pythonanywhere.com
  

• Verify the tunnel is working: Run telnet 127.0.0.1 3306 (or 3307) — if it connects, the tunnel is up. The TIME_WAIT state in netstat just means a previous connection is in the closing phase; as long as telnet works, the tunnel is usable.

For PuTTY: #

If you're using PuTTY for tunneling, double-check these settings:

1. Go to Connection > SSH > Tunnels
2. Enter 3306 (or 3307) as the Source port
3. Enter jonathanbechtel.mysql.pythonanywhere-services.com:3306 as the Destination
4. Select Local and Auto, then click Add
5. Log into your PythonAnywhere SSH session and keep the PuTTY window open

Third: Configure Tableau Correctly #

Once your tunnel is active, set up Tableau's MySQL connection like this:

• Server: 127.0.0.1 (use this instead of localhost to avoid DNS resolution issues)
• Port: The port you used for your tunnel (3306 or 3307)
• Username: The full PythonAnywhere MySQL username (e.g., jonathanbechtel$root)
• Password: Your MySQL database password (not your PythonAnywhere SSH password)
• Database: Your full PythonAnywhere database name (e.g., jonathanbechtel$mydatabase)

Also, make sure you're using the MySQL ODBC 8.0 Driver (match the bitness to your Tableau installation—64-bit Tableau needs 64-bit drivers, 32-bit needs 32-bit). Avoid the "MySQL Legacy" driver as it can cause compatibility issues.

Why Does the Python Code Work? #

Your Python script uses the sshtunnel library which handles the port forwarding correctly, and you're passing the full formatted MySQL username via info['username']. The key difference is that Tableau was missing the full username string.

Quick Validation Steps #

To rule out other issues:

1. Test the tunnel with MySQL Workbench: Use 127.0.0.1:3306, the full username, and DB password. If it connects, the tunnel and permissions are good.
2. Test with the MySQL command line:

   mysql -h 127.0.0.1 -P 3306 -u jonathanbechtel$root -p
   

   Enter your DB password—if you can log in, the problem is definitely in Tableau's configuration.

内容的提问来源于stack exchange，提问作者Jonathan Bechtel