Composable SQL: A Functional Approach to Solving SQL Testing and Business Logic Problems

This article explores the shortcomings of SQL in testing and reusing business logic, proposing a solution called "functors"—composable SQL fragments. By parameterizing queries and relying on interfaces instead of concrete tables, functors solve the challenges of SQL testing and allow for business logic reuse across queries, improving code readability, testability, and reusability. The author also discusses extensions such as generics, generalizing business logic, and avoiding global variables, ultimately achieving efficient, testable, and understandable SQL queries.