How do I log SQL errors in a secure and informative way in PHP?

For secure logging, use a dedicated logging system like Monolog or Simple Logger. Avoid logging sensitive information (like passwords) in plain text. Include relevant information in the log message, such as the database connection details, the SQL query, and the user who triggered the error. Consider using a log level (e.g., DEBUG, INFO, WARNING, ERROR) to control the amount of information logged.