Are you doing TDD? Can you explain the differences between insert, update, and delete operations?

TDD, or Test‑Driven Development, is a software development practice where tests are written before the code that implements the functionality. In the context of database operations, the three primary CRUD actions are Insert, Update, and Delete. Insert adds a new record to a table; it requires all mandatory columns to be supplied and typically returns the new primary key. Update modifies existing data; it uses a WHERE clause to target specific rows and can change one or many columns. Delete removes rows from a table; it also uses a WHERE clause to specify which rows to remove. In TDD, you would write unit tests that assert the expected state of the database after each operation, ensuring that insert, update, and delete behave correctly and that data integrity constraints are respected.