Database APIs are currently experiencing something of a renaissance. At first glance, the idea of accessing a database directly through an API seems ideal.
In this article, I want to shed light on why database APIs cause more problems than they solve in the long run, and how they undermine the principles of sustainable and scalable API design. I'll also explain why API best practices are key to future-proofing systems.
What is a database API?
A database API is an interface that allows developers to interact directly with a database, whether through SQL-like queries or direct SQL commands. Unlike well-designed APIs, which provide an abstraction layer between business logic and data, database APIs often focus on manipulating raw data. Developers can use these APIs to execute database queries as if they were working directly with the database.
While this may seem efficient, it creates very tight dependencies between consumers and the database structure. As soon as changes are made to the database, for example by adjusting the table structures, the consumers are also affected. This close coupling leads to high maintenance costs and increases the likelihood of errors in future changes.
The problem with database APIs
The heart of the problem with database APIs is that they ignore fundamental design principles that make an API sustainable and scalable. A well-designed API provides its users with an abstracted interface that allows them to access data without knowing the underlying complexity. Database APIs, on the other hand, provide direct access to the database, which has profound implications for the architecture of a system.
One of the most serious implications is the tight coupling between the API and the database. This direct connection means that any change to the database requires changes to the API consumers, leading to 'breaking changes' and an unstable system. This goes against the whole idea of API versioning and backwards compatibility, which are necessary to ensure consistency in an API ecosystem.
Another problem is that database APIs often violate the Single Responsibility Principle (SRP). APIs should not only provide data, but also encapsulate and process business logic. Database APIs often skip this step, meaning that essential logic is either not implemented at all or is pushed to the consumer. This division of responsibility leads to inconsistencies and an increased susceptibility to errors in the system.
Good API Design vs. Database APIs
Unlike database APIs, good API design follows clear principles aimed at flexibility, security and consistency. APIs should not only transport data, but also encapsulate business logic and provide consumers with an abstracted view of the underlying complexity.
A key difference between database APIs and good API design is the separation of responsibilities. While database APIs often provide direct access to data, a well-designed API is an independent layer that focuses on the processing and presentation of data. This independence makes it possible to change the internal structure of the database without affecting consumers.
In addition, a clean versioning strategy allows developers to make changes to the API without affecting existing users. Database APIs, on the other hand, tend to tie consumers tightly to the underlying database, resulting in a system that is difficult to maintain and rigid in the long term.
Why an API-first approach helps
An API-first approach focuses on the consumers of the API and their needs before the actual implementation begins. APIs are treated as standalone products that not only meet technical requirements, but also provide consistent, reusable and easy-to-use interfaces.
Unlike database APIs, which are often tied to the internal database structure, the API-first approach allows a clear separation between the API and the internal systems. This results in a flexible and adaptable architecture that remains stable over time.
By closely involving API consumers in the design process, APIs are developed that are not only functional, but also meet user requirements. This is in stark contrast to database APIs, where the internal logic is often difficult to understand and impractical for consumers.
Conclusion
At first glance, database APIs may seem like a tempting solution for accessing data quickly and directly. But this convenience comes at a cost. They break with the basic principles of good API design, such as abstraction, flexibility and security. In the long run, database APIs lead to rigid, difficult-to-maintain architectures that do not meet the needs of modern, scalable systems.
The right approach is sound API design that creates a clear separation between business logic and the database, treats APIs as independent services, and provides consumers with an abstracted, flexible and secure interface.