Lume

A type-safe, ergonomic schema builder and ORM for SQL databases, inspired by Drizzle ORM.

Features

• 🚀 Type-safe: Compile-time type checking for all database operations
• 🎯 Ergonomic: Clean, intuitive API inspired by modern ORMs
• ⚡ Performance: Zero-cost abstractions with minimal runtime overhead
• 🔧 Flexible: Support for various column constraints and SQL types
• 🛡️ Safe: Prevents SQL injection and runtime type errors
• 📦 Lightweight: Minimal dependencies, maximum functionality

Quick Start

Add Lume to your Cargo.toml:

[dependencies]
lume = "0.1"
tokio = { version = "1.0", features = ["macros", "rt-multi-thread"] }

Basic Usage

use lume::define_schema;
use lume::schema::Schema;

// Define your database schema
define_schema! {
    Users {
        id: i32 [primary_key().not_null()],
        username: String [not_null()],
        email: String,
        age: i32,
        is_active: bool [default_value(true)],
        created_at: i64 [not_null()],
    }

    Posts {
        id: i32 [primary_key().not_null()],
        title: String [not_null()],
        content: String,
        author_id: i32 [not_null()],
        published: bool [default_value(false)],
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Connect to your MySQL database
    let db = Database::connect("mysql://user:password@localhost/database").await?;

    // Create tables (if they don't exist)
    Users::ensure_registered();
    Posts::ensure_registered();

    // Type-safe queries
    let users = db
        .query::<Users>()
        .filter(lume::filter::Filter::eq("username", "john_doe"))
        .execute()
        .await?;

    for user in users {
        let username: Option<String> = user.get(Users::username());
        let age: Option<i32> = user.get(Users::age());
        println!("User: {} (age: {})", username.unwrap_or_default(), age.unwrap_or(0));
    }

    Ok(())
}

Schema Definition

Lume provides a powerful macro system for defining database schemas:

define_schema! {
    Product {
        id: i32 [primary_key().not_null()],
        name: String [not_null().unique()],
        description: String,
        price: f64 [not_null()],
        stock: i32 [default_value(0)],
        category_id: i32 [not_null().indexed()],
        created_at: i64 [not_null()],
        updated_at: i64 [not_null()],
    }
}

Supported Types

• String → VARCHAR(255)
• i32 → INTEGER
• i64 → BIGINT
• f32 → FLOAT
• f64 → DOUBLE
• bool → BOOLEAN

Column Constraints

• primary_key() - Sets the column as primary key
• not_null() - Makes the column NOT NULL
• unique() - Adds a UNIQUE constraint
• indexed() - Creates an index on the column
• default_value(value) - Sets a default value

Type-Safe Queries

// Filter by equality
let active_users = db
    .query::<Users>()
    .filter(Filter::eq("is_active", true))
    .execute()
    .await?;

// Multiple filters
let young_active_users = db
    .query::<Users>()
    .filter(Filter::eq("is_active", true))
    .filter(Filter::lt("age", 25))
    .execute()
    .await?;

// Access row data type-safely
for user in young_active_users {
    let id: Option<i32> = user.get(Users::id());
    let username: Option<String> = user.get(Users::username());
    let email: Option<String> = user.get(Users::email());

    println!("User {}: {} ({})", id.unwrap_or(0), username.unwrap_or_default(), email.unwrap_or_default());
}

Advanced Features

Custom Default Values

define_schema! {
    Settings {
        id: i32 [primary_key().not_null()],
        theme: String [default_value("dark".to_string())],
        notifications: bool [default_value(true)],
        max_connections: i32 [default_value(10)],
    }
}

Table Relationships

define_schema! {
    Author {
        id: i32 [primary_key().not_null()],
        name: String [not_null()],
        email: String [not_null().unique()],
    }

    Book {
        id: i32 [primary_key().not_null()],
        title: String [not_null()],
        author_id: i32 [not_null()], // References Author.id
        published_year: i32,
        isbn: String [unique()],
    }
}

Error Handling

Lume provides comprehensive error handling:

use lume::database::DatabaseError;

match db.query::<Users>().execute().await {
    Ok(users) => {
        println!("Found {} users", users.len());
    }
    Err(DatabaseError::ConnectionFailed) => {
        eprintln!("Failed to connect to database");
    }
    Err(DatabaseError::QueryFailed) => {
        eprintln!("Query execution failed");
    }
    Err(e) => {
        eprintln!("Unexpected error: {:?}", e);
    }
}

Testing

Lume includes comprehensive unit tests:

cargo test

Run specific test categories:

cargo test schema    # Schema definition tests
cargo test row       # Row manipulation tests
cargo test value     # Value conversion tests
cargo test registry  # Table registry tests

Contributing

Contributions are welcome! Please read our contributing guidelines and submit pull requests for any improvements.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Changelog

See CHANGELOG.md for a detailed list of changes and improvements.