Documentation

Welcome to FlyQL project documentation. Current version is 0.0.52 (changelog).

FlyQL is a lightweight, human-readable query language designed for filtering data. It transpiles into injection-proof SQL across ClickHouse, PostgreSQL, and StarRocks — with full implementations in Go, Python, and JavaScript. Write a query once, and FlyQL generates dialect-specific SQL for your database — or evaluates it in-memory against data records.

status >= 400 and host like 'prod%' and not debug

This query works identically whether your backend is ClickHouse, PostgreSQL, StarRocks, or an in-memory dataset.

Key Features

• Injection-Proof by Design — The grammar cannot express subqueries, JOINs, UNIONs, or DDL. Security is structural, not defensive. All values are escaped in the generated SQL.
• Multi-Dialect SQL — One query language, dialect-specific output. Generates correct SQL for ClickHouse, PostgreSQL, and StarRocks with proper type handling (JSON paths, Map access, Array handling).
• Multi-Language — Full implementations in Go, Python, and JavaScript. Parse on the frontend, validate on the backend, generate SQL anywhere — same query, same results.
• Parameterized Queries — $name and $1 placeholders that are resolved at runtime via bindParams(). Template a query once, bind values safely later — no string concatenation, no escaping by hand.
• Minimal Dependencies — Hand-written state-machine parser with zero external dependencies in Go and JavaScript. Python pulls in google-re2 for RE2-safe regex matching. Trivial to integrate, nothing to conflict with.

Quick Example

service != api and (status >= 400 or level = error) and message ~ "timeout.*"

Component	Meaning
service != api	service field is not "api"
status >= 400	status is 400 or greater
level = error	level field equals "error"
message ~ "timeout.*"	message matches regex pattern
and, or	boolean logic, standard precedence (not > and > or)
( )	explicit grouping

Supported Languages

Language	Parser	In-Memory Matcher
Go	Yes	Yes
Python	Yes	Yes
JavaScript	Yes	Yes

SQL Generators

Database	Go	Python	JavaScript
ClickHouse	Yes	Yes	Yes
PostgreSQL	Yes	Yes	Yes
StarRocks	Yes	Yes	Yes