Module parser 

Query Statement Parser

Lightweight keyword-based parser for CQL DML statements in the query engine.

Purpose

This module parses SELECT, INSERT, UPDATE, and DELETE statements for execution by the M2+ query engine. It uses keyword extraction rather than full AST parsing to provide fast, lightweight query handling.

Architecture Context

This is one of four parsing subsystems in cqlite-core:

Module	Purpose
cql/	Full CQL text → AST parsing
parser/	SSTable binary format parsing
schema/cql_parser.rs	CREATE TABLE → TableSchema
query/parser.rs	DML → ParsedQuery (this module)

See docs/architecture/parser-overview.md for the complete architecture overview.

Key Components

• QueryParser - Main parser struct with parse() method
• M2SelectValidator - Validates SELECT queries against M2 supported subset
• ParsedQuery - Structured query representation

Supported Statements

• SELECT - With WHERE (equality only for M2), ORDER BY, LIMIT
• INSERT - Explicit or implicit column syntax
• UPDATE - SET clause with WHERE
• DELETE - FROM with WHERE
• CREATE TABLE / DROP TABLE - Table name extraction
• DESCRIBE / USE - Basic keyword parsing

Example

use cqlite_core::query::QueryParser;

let parser = QueryParser::new(&config);
let query = parser.parse("SELECT * FROM users WHERE id = 1 LIMIT 10")?;
assert_eq!(query.query_type, QueryType::Select);

M2 Limitations

The M2 milestone supports a subset of CQL SELECT:

• Partition key equality filters only (=)
• No range operators (>, <, >=, <=)
• No aggregates (COUNT, SUM, etc.)
• No ALLOW FILTERING

For advanced CQL parsing with full AST support, use the crate::cql module.

Structs

QueryParser

CQL query parser