Fix SQL window function query syntax

[jeffreyaven]

Add experimental support for SQL window functions (OVER clause) and CTEs (WITH clause) to the parser via a local fork of stackql-parser.

Window function features:

• OVER clause with optional PARTITION BY and ORDER BY
• Frame specifications (ROWS/RANGE BETWEEN)
• All standard frame boundary types

CTE features:

• Simple and multiple CTEs
• Recursive CTEs with WITH RECURSIVE
• Optional column list specification

This is a proof-of-concept implementation for testing feasibility. The changes are in a local fork at internal/stackql-parser-fork/ with a replace directive in go.mod.

Includes:

• Parser unit tests for both features (all passing)
• Documentation of implementation details and next steps

Description

Type of change

• Bug fix (non-breaking change to fix a bug).
• Feature (non-breaking change to add functionality).
• Breaking change.
• Other (eg: documentation change). Please explain.

Issues referenced.

Evidence

Checklist:

• A full round of testing has been completed, and there are no test failures as a result of these changes.
• The changes are covered with functional and/or integration robot testing.
• The changes work on all supported platforms.
• Unit tests pass locally, as per the developer guide.
• Robot tests pass locally, as per the developer guide.
• Linter passes locally, as per the developer guide.

Variations

Tech Debt