How to resolve the issue of unsuccessful SQL connection testing?

If the SQL connection fails, you can try the following solutions:

1. Check the connection string: verify that the server name, database name, username, and password in the connection string are correct. Ensure that the format of the connection string is correct.
2. Check network connection: Ensure that the network connection between your computer and the database server is functioning properly. You may use the ping command to test the connectivity.
3. Check the database server: make sure the database server is running and accepting connection requests from your computer. You can try using a database management tool to connect to the database server to verify that it is running properly.
4. Check the firewall settings: If a firewall is enabled on your computer or database server, make sure to allow inbound connections to the database server port.
5. Check the database permissions: Make sure your database user has sufficient permissions to connect and access the database. You can try connecting with a database user that has higher permissions.
6. Check the database configuration: Review the configuration file of the database server to ensure it allows remote connections. Some databases require explicit configuration in the file to allow remote connections.
7. Check the database engine: If you are using a specific database engine such as MySQL or SQL Server, make sure it has been installed and configured correctly.

If none of the above solutions resolve the issue, consider reaching out to the database administrator or technical support for assistance.