This article explains why MySQL discourages using NULL as a default column value, demonstrates how NULL affects indexing, comparisons, and aggregate functions, and shows through concrete examples that improper NULL handling can lead to unexpected query results and performance degradation.
The article explains that an aggregate is defined by the business invariants that must stay strongly consistent, shows how the aggregate root protects those rules, and provides concrete design principles—ID references, single‑aggregate transactions, small boundaries, validation tests, and common pitfalls—illustrated with an order domain example.
This article explains why domain models are needed, walks through DDD's strategic and tactical design concepts, demonstrates a full knowledge‑payment platform case with bounded contexts, aggregates, and ubiquitous language, and outlines practical guidelines and limitations for applying DDD in real projects.
This article delves into the tactical design of Domain‑Driven Design, explaining core building blocks such as entities, value objects, aggregates, domain events, repositories, application services, and domain services, and shows how they help keep business logic centralized and expressive.
The article explains how software complexity arises from scale, structure, and change, and shows that controlling dependencies through bounded contexts and aggregates—by reducing dependency quantity and weakening dependency strength—provides a practical way to achieve high cohesion and low coupling in system architecture.
The article explains how software complexity stems from scale, structure, and change, and shows that controlling dependencies—by reducing their number and weakening their strength—through bounded contexts and aggregates is the key to achieving high cohesion and low coupling in domain‑driven design.
