Recursive CTEs: SQL’s Hidden Graph Traversal Engine

Recursive Common Table Expressions (CTEs) in SQL offer a powerful, built-in method for handling graph-like problems without needing specialized databases or libraries. This feature allows for iterative querying to traverse hierarchical data and networks, often replacing the need for tools like Neo4j or NetworkX for smaller datasets. The process involves an anchor query to establish a starting point, followed by a recursive query that joins back to itself to build upon the results. Practical examples demonstrate how to navigate an organizational chart and find all possible paths and costs in a transportation network using only standard SQL.