How Does SQLite Handle Recursive Queries, Especially Before and After Version 3.8.3?

SQLite's Recursive Query Capabilities

Despite initial limitations, SQLite now offers robust recursive query support with the introduction of Common Table Expressions (CTEs) in version 3.8.3 and above. This enhancement enables the formulation of powerful recursive queries that traverse hierarchical structures.

Recursive CTE Implementation:

Utilizing the WITH clause, you can define recursive CTEs as follows:

WITH RECURSIVE CTE_Name AS (
    SELECT ...
    UNION ALL
    SELECT ...
)
SELECT ... FROM CTE_Name

This syntax allows you to define a recursive query that iteratively expands, similar to traditional SQL recursion.

Pre-3.8.3 Recursive Query Emulation:

Prior to version 3.8.3, SQLite did not natively support recursive CTEs. To emulate recursion, you had to resort to a procedural approach:

1. Retrieve Initial Row and Sub-part IDs:

   • Grab the initial row for the given SuperPart.
   • Extract and store the SubPart IDs for the initial row.

2. Iterative Retrieval of Sub-part Data:

   • Fetch the rows and SubPart IDs for each sub-part.
   • Append these rows to the initial row set.

3. Continue Iteration:

   • Repeat steps 1-2 until no new sub-parts are found.

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