qcraft

Universal, extensible SQL query builder for Rust.

Build SQL statements as typed AST nodes, then render them to parameterized SQL for any supported dialect. One AST, many backends.

Features

• AST-first design -- queries are data structures, not string templates
• PostgreSQL + SQLite support out of the box, more dialects planned
• Parameterized queries -- every render returns (String, Vec<Value>), never interpolates user data
• Extensible via Custom traits -- add custom expressions, conditions, compare operators, table sources, and mutations without forking
• Convenience API -- helpers like SelectColumn::field(), Conditions::gte(), InsertStmt::values() to build statements in a few lines
• Full SQL coverage -- SELECT, INSERT, UPDATE, DELETE, DDL (CREATE/ALTER/DROP), transactions, CTEs, window functions, set operations, locking, upsert

Installation

cargo add qcraft

Both postgres and sqlite features are enabled by default. To use only one:

cargo add qcraft --no-default-features --features postgres
cargo add qcraft --no-default-features --features sqlite

Quick Start

SELECT with WHERE

use qcraft::ast::common::{FieldRef, SchemaRef};
use qcraft::ast::conditions::Conditions;
use qcraft::ast::query::{FromItem, QueryStmt, SelectColumn};

let stmt = QueryStmt {
    columns: vec![SelectColumn::field("users", "name")],
    from: Some(vec![FromItem::table(SchemaRef::new("users"))]),
    where_clause: Some(Conditions::gte(FieldRef::new("users", "age"), 18)),
    ..Default::default()
};

Rendering -- PostgreSQL

use qcraft_postgres::PostgresRenderer;

let (sql, params) = PostgresRenderer::new().render_query_stmt(&stmt).unwrap();
// sql:    SELECT "users"."name" FROM "users" WHERE "users"."age" >= $1
// params: [Int(18)]

Rendering -- SQLite

use qcraft_sqlite::SqliteRenderer;

let (sql, params) = SqliteRenderer::new().render_query_stmt(&stmt).unwrap();
// sql:    SELECT "users"."name" FROM "users" WHERE "users"."age" >= ?
// params: [Int(18)]

Same AST, different output. Parameters are always separated from the SQL string.

INSERT with values

use qcraft::ast::dml::{InsertStmt, MutationStmt};
use qcraft::ast::expr::Expr;

let insert = InsertStmt::values(
    "users",
    vec!["name", "email"],
    vec![vec![Expr::value("Alice"), Expr::value("alice@test.com")]],
);
let stmt = MutationStmt::Insert(insert);

let (sql, params) = PostgresRenderer::new().render_mutation_stmt(&stmt).unwrap();
// sql:    INSERT INTO "users" ("name", "email") VALUES ($1, $2)
// params: [Str("Alice"), Str("alice@test.com")]

let (sql, params) = SqliteRenderer::new().render_mutation_stmt(&stmt).unwrap();
// sql:    INSERT INTO "users" ("name", "email") VALUES (?, ?)
// params: [Str("Alice"), Str("alice@test.com")]

Performance

qcraft is 3.5x–14.6x faster than sea-query and uses up to 8.9x less memory per query. Benchmarks measure parameterized SQL rendering to PostgreSQL:

Scenario	qcraft	sea-query	Speedup
Simple SELECT + WHERE	201 ns	1,345 ns	6.7x
JOIN + GROUP BY + ORDER BY + LIMIT	362 ns	3,168 ns	8.8x
INSERT (3 rows)	479 ns	1,662 ns	3.5x
Complex CTE + JOIN + GROUP BY + HAVING	489 ns	7,152 ns	14.6x

See full benchmark results for memory allocation details and methodology.

Crate Structure

Crate	Description
qcraft	Umbrella crate -- re-exports core + dialect crates
qcraft-core	AST types, Renderer trait, render context
qcraft-postgres	PostgresRenderer -- PG-specific SQL generation
qcraft-sqlite	SqliteRenderer -- SQLite-specific SQL generation

Documentation

• Getting Started
• SELECT Queries
• INSERT / UPDATE / DELETE
• Schema Management (DDL)
• Transactions
• Parameterized Queries
• Multi-Dialect Rendering
• Extensibility
• Type Reference
• Architecture
• Benchmarks

License

MIT OR Apache-2.0