Can you tell how you would handle a schema violation?

A schema violation occurs when data being inserted or updated does not conform to the defined table structure, such as violating a NOT NULL constraint, foreign key, or data type mismatch. To handle it, I would first log the error with contextual information (table, column, offending value, timestamp, user). Then, I would decide on a recovery strategy based on business rules:

1. Fail fast – roll back the transaction and return a clear error message to the caller, ensuring data integrity.
2. Data sanitization – transform or truncate the offending value to fit the schema (e.g., trim strings, cast types) before retrying.
3. Default values – supply a default or placeholder when a NOT NULL constraint is violated.
4. Schema evolution – if the violation is due to a recent schema change, consider adding a migration script or altering the table to accommodate new data.
5. Alerting – trigger alerts for repeated violations to investigate root causes.

In production, I would wrap the operation in a try/catch block, use database transaction controls, and ensure that any compensating actions are idempotent. This approach balances data integrity, user experience, and maintainability.