How do you encrypt data in SQL Server, PostgreSQL, or MySQL?

Short answer: Encryption is essential for protecting sensitive data both at rest (on disk) and in transit (during communication).

Explain a bit more

SQL Server: Transparent Data Encryption (TDE): Encrypts data at rest without requiring application changes. CREATE DATABASE ENCRYPTION KEY; ALTER DATABASE MyDatabase SET ENCRYPTION ON; Column-Level Encryption: For encrypting specific columns. CREATE CERTIFICATE MyCertificate WITH SUBJECT = 'My Certificate'; CREATE SYMMETRIC KEY MySymmetricKey WITH ALGORITHM = AES_256 ENCRYPTION BY CERTIFICATE MyCertificate; OPEN SYMMETRIC KEY MySymmetricKey DECRYPTION BY CERTIFICATE MyCertificate; PostgreSQL: pgcrypto extension provides functions for encrypting data. SELECT pgp_sym_encrypt('Sensitive Data', 'encryption_key'); MySQL: Encryption Functions: MySQL provides functions like AES_ENCRYPT and AES_DECRYPT. SELECT AES_ENCRYPT('Sensitive Data', 'encryption_key'); SELECT AES_DECRYPT(encrypted_data, 'encryption_key'); For all databases, consider using SSL/TLS for encrypting data in transit.

Real-world example (ShopNest)

ShopNest’s SQL Server database stores customers, products, and orders. Good indexes and clear foreign keys keep checkout queries fast and safe.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.