Recursive CTEs: SQL’s Hidden Graph Traversal Engine

📰 Medium · Python

Learn to use Recursive CTEs in SQL to traverse graphs and hierarchies, and solve complex problems like finding routes and detecting cycles

intermediate Published 25 Sept 2026

Action Steps

Define a recursive Common Table Expression (CTE) to traverse a graph or hierarchy
Use the recursive CTE to find routes between nodes
Detect cycles in the graph using the recursive CTE
Calculate degrees of separation between nodes
Apply the recursive CTE to real-world problems like organizational charts or social networks

Who Needs to Know This

Data analysts and engineers can benefit from this technique to query and analyze complex data relationships, and software engineers can use it to optimize their database queries

Key Insight

💡 Recursive CTEs can be used to traverse graphs and hierarchies, and solve complex problems like finding routes and detecting cycles