qail-core

The AST-native query builder — No SQL strings, no ORM magic, just type-safe expressions.

Why AST-Native?

Approach	How it works	Safety Level
String-based	SQL as strings	Requires parameterization
ORM	Macros generate SQL	Compile-time safe
AST-Native (QAIL)	Typed AST → Wire protocol	Structurally safe

QAIL builds queries as an Abstract Syntax Tree that compiles directly to database wire protocol. There's no SQL string generation step—safety is built into the design.

Installation

[!CAUTION] Alpha Software: QAIL is currently in alpha. While we strive for stability, the API is evolving to ensure it remains ergonomic and truly AST-native. Do not use in production environments yet.

[dependencies]
qail-core = "0.13.1"

Quick Start

use qail_core::{Qail, Operator};
use qail_core::ast::builders::*;

// Build a query as typed AST
let cmd = Qail::get("users")
    .columns([col("id"), col("name"), col("email")])
    .filter(eq("active", true))
    .order_by([("created_at", Desc)])
    .limit(10);

// Use with qail-pg driver
let rows = driver.fetch_all(&cmd).await?;

Ergonomic Expression Builders

use qail_core::ast::builders::*;

// Aggregates with FILTER
count_filter(vec![eq("status", "active")]).alias("active_users")

// Time expressions  
now_minus("24 hours")  // NOW() - INTERVAL '24 hours'

// CASE WHEN
case_when(gt("score", 80), text("pass"))
    .otherwise(text("fail"))
    .alias("result")

// Type casting
cast(col("amount"), "float8")

Features

Type-safe expressions — Compile-time checked query building
Ergonomic builders — count(), sum(), case_when(), now_minus()
Full SQL support — CTEs, JOINs, DISTINCT ON, aggregates with FILTER
JSON operators — ->, ->>, @>, ?
Schema parser — Parse DDL into structured AST

Ecosystem

Crate	Purpose
qail-core	AST builder, parser, expression helpers
qail-pg	PostgreSQL driver (AST → wire protocol)
qail	CLI tool for migrations and schema ops

License

MIT

🤝 Contributing & Support

We welcome issue reports on GitHub! Please provide detailed descriptions to help us reproduce and fix the problem. We aim to address critical issues within 1-5 business days.

qail-core 0.14.2