Data Integrity and Validation Patterns

In this section

• Enforcing Data Integrity with Constraints
  Use primary key, foreign key, unique, and check constraints to enforce identity, relationships, uniqueness, and valid domains.
• SQL Data Validation Techniques
  Design SQL validation with defaults, constraints, input checks, and server-side rules that prevent invalid data from persisting.
• Business Logic in SQL Databases
  Decide when business rules belong in SQL procedures, triggers, constraints, or application services.
• Cascading Updates and Deletes in SQL
  Use cascading foreign-key actions deliberately to preserve referential integrity without deleting or updating more rows than intended.
• SQL Auditing and Change Tracking
  Track SQL data changes with audit tables, triggers, and Change Data Capture while planning retention, privacy, and diagnostics.
• SQL Triggers for Data Integrity
  Use SQL triggers for integrity, auditing, and derived data only when implicit side effects are justified and observable.
• Stored Procedures for Data Access Control
  Use stored procedures to expose controlled SQL operations, reduce direct table access, and enforce consistent security checks.
• SQL Exception and Error Handling
  Handle SQL exceptions with TRY...CATCH, THROW or RAISERROR, transaction rollback, and diagnostic logging.