Can a Single MySQL Query Traverse Tree Structures to Any Depth?

Querying Tree Structures to Unlimited Depth in MySQL with a Single Query

Exploring the possibility of querying tree structures in MySQL to any depth with a single query, it was previously thought to be impossible. However, a technique known as Modified Preorder Tree Traversal offers a solution.

According to Joe Celko's book, "Trees and Hierarchies in SQL for Smarties," this traversal allows for querying descendants and ancestors regardless of their depth in the tree. A working example is also available in PHP from Sitepoint: http://www.sitepoint.com/article/hierarchical-data-database/2/.

This opens up significant possibilities for managing tree structures in MySQL. It eliminates the need for recursive queries or complex joins, resulting in more efficient and concise code. However, it's important to note that this technique requires a properly structured tree table with a "parent_id" column.

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