Explain SQL injection types: in-band, blind, and out-of-band, and how they are detected.

SQL injection types include In-band, Blind, and Out-of-band. In-band, or error-based/union-based, returns data directly in the application's response, detected by observing error messages or union query results. Blind SQLi, like boolean-based or time-based, doesn't return data directly; detection relies on observing application behavior changes (e.g., page load times or true/false responses). Out-of-band SQLi uses the database server's out-of-band communication capabilities, such as DNS or HTTP requests, to exfiltrate data, detected by monitoring network traffic for unusual outbound connections from the database server. Bangalore companies like Wipro and Infosys often test for practical detection skills using tools like SQLMap.