[Refactor] Query Parser Fix After AST Support

[HazelYuAhiru]

Overview

This PR updates the query parser logic to support more complex test cases. All existing test cases now pass.

[Copilot]

Pull request overview

This PR refactors the SQL-to-AST query parser to handle a broader set of mo_sql_parsing constructs (e.g., DISTINCT/DISTINCT ON, IN literal lists, CASE, INTERVAL/EXTRACT, NULL/IS NULL), and updates the test suite to re-enable many previously disabled parser/AST equality assertions.

Changes:

• Expanded core/query_parser.py to parse additional SQL constructs into the project’s AST node types (e.g., ListNode, CaseNode, IntervalNode, DataTypeNode, DISTINCT ON support).
• Adjusted alias handling across clauses (notably GROUP BY / WHERE comments and resolution behavior).
• Re-enabled many tests/test_query_parser.py assertions, while leaving test_basic_parse and test_query_42 effectively disabled pending design decisions.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
tests/test_query_parser.py	Re-enables most parser-vs-expected-AST assertions, but leaves two key tests disabled via commented asserts.
core/query_parser.py	Adds parsing support for DISTINCT(+ON), IN lists/subqueries, NULL/IS NULL, CASE, INTERVAL, EXTRACT, and tweaks alias resolution logic.

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[Copilot]

Pull request overview

This PR refactors and extends the SQL-to-AST query parser to support more complex query patterns emitted by mo_sql_parsing, with the goal of turning previously-disabled parser tests back on.

Changes:

• Expanded QueryParser to handle additional SQL constructs (e.g., DISTINCT / DISTINCT ON, IN literal lists, INTERVAL, EXTRACT, CASE, NULL normalization).
• Adjusted alias resolution behavior across clauses (notably GROUP BY, ORDER BY, and WHERE) to better match expected AST semantics.
• Re-enabled many previously-commented test assertions (while leaving a couple still disabled).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
core/query_parser.py	Adds parsing support for more AST node types and improves clause parsing/alias resolution to satisfy more real-world queries.
tests/test_query_parser.py	Re-enables many parser equality assertions; still has two key tests with assertions commented out.
data/asts.py	Minor comment/TODO update on GROUP BY ordinal handling in Query 42 expected AST.

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[Copilot]

Pull request overview

This PR updates the SQL → AST query parser to handle additional SQL constructs (e.g., DISTINCT/DISTINCT ON, CASE, INTERVAL/EXTRACT, IN-lists, NULL/IS NULL), and re-enables previously commented-out parser assertions so the expanded suite is executed.

Changes:

• Re-enabled assert parser.parse(sql) == get_ast(...) checks across many query parser tests.
• Extended core/query_parser.py to support more mo_sql_parsing AST shapes and SQL features (DISTINCT/DISTINCT ON, CASE, INTERVAL, IN literal lists/subqueries, NULL/IS NULL).
• Minor fixture comment tweak in data/asts.py.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
tests/test_query_parser.py	Uncomments parser-vs-fixture asserts so the full set of query AST expectations is enforced.
data/asts.py	Updates a comment in query 42’s expected AST fixture.
core/query_parser.py	Adds parsing support for additional SQL constructs required by the expanded tests (distinctness, CASE, intervals, IN lists, NULL checks, alias handling).

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