Why Am I Getting 'Unable to Connect to Specified MySQL Hosts' in C#?

Troubleshooting "Unable to Connect to Specified MySQL Hosts" Error in C#

When encountering the error "Unable to connect to any of the specified MySQL hosts" while executing MySQL connection code in C#, it's crucial to examine several aspects:

Connection String Parameters:

As outlined in the provided answer, the order and spacing of parameters within the connection string can be critical. Ensure that the connection string adheres to the standard format:

Server=myServerAddress; Port=1234; Database=myDataBase; Uid=myUsername; Pwd=myPassword;

Installation Issues:

Verify that you have installed the appropriate MySQL connector and that the required references are added to your project. In Visual Studio or SharpDevelop, check under the References tab if the MySQL connector assembly is present.

Firewall and Permissions:

Ensure that the MySQL server is accessible from your application and that the necessary firewall ports are open. Additionally, check the user permissions to verify that your application has the required privileges to connect to the MySQL database.

SharpDevelop Compatibility:

As mentioned in the problem, the error may occur when using SharpDevelop but not Visual Studio. This could indicate a compatibility issue with SharpDevelop or its extensions. Try using Visual Studio or investigate potential issues with SharpDevelop's MySQL support.

Debugging with Exception Details:

In the error message provided, you can find additional information about the underlying exception:

• Server Error Code: 1042 indicates a Server Not Found error.
• Exception Type: MySqlException reveals the exception is specific to MySQL connectivity.

These details can help you focus your troubleshooting efforts.

Additional Tips:

• Try using different connection strings (e.g., with and without port specification) to isolate the issue.
• Check the MySQL server logs for any connectivity errors or warnings.
• Use a network tool like Wireshark to monitor the network traffic between the application and the MySQL server.

The above is the detailed content of Why Am I Getting 'Unable to Connect to Specified MySQL Hosts' in C#?. For more information, please follow other related articles on the PHP Chinese website!