Strategy Pattern Can Replace Bloated SQL Queries in Role-Based App Search

A software engineering article on DEV Community argues that complex, role-based SQL search queries should be treated as structured application logic rather than dynamically assembled strings. The piece demonstrates how a legacy approach — appending filters and role conditions to a single StringBuilder method — produces unmaintainable, hard-to-test code that can obscure security boundaries. The author proposes applying the Strategy design pattern twice: one set of strategies governs what data a user is permitted to see based on their role, while another handles the optional search filters a user applies. A companion demo repository illustrates both approaches against the same SQL Server schema, using Spring Boot, Spring JDBC, and Testcontainers for real-database testing. The article covers five distinct user roles with differing visibility rules and ten optional filters, highlighting how the composed approach makes each rule independently addressable and reviewable.