Georm 0.2.0 - Major Feature Release

We're excited to announce Georm 0.2.0, a major release packed with new features, performance improvements, and comprehensive documentation updates! 🚀

What's New

🆕 Major Features

Composite Primary Key Support

• Multi-field primary keys: Use multiple #[georm(id)] fields to create composite primary keys
• Auto-generated ID structs: Automatically creates {EntityName}Id structs for type-safe composite key handling
• Full CRUD support: All operations (find, create, update, delete, create_or_update) work seamlessly with composite keys

#[derive(Georm)]
#[georm(table = "user_roles")]
pub struct UserRole {
    #[georm(id)]
    pub user_id: i32,
    #[georm(id)]
    pub role_id: i32,
    pub assigned_at: chrono::DateTime<chrono::Utc>,
}

// Auto-generated ID struct
let id = UserRoleId { user_id: 1, role_id: 2 };
let user_role = UserRole::find(pool, &id).await?;

Defaultable Fields with Companion Structs

• Database defaults support: Mark fields with #[georm(defaultable)] for auto-generated or default values
• Companion struct generation: Creates {Entity}Default structs where defaultable fields become Option<T>
• Easier entity creation: Simplifies creating entities when some fields have database defaults

#[derive(Georm)]
#[georm(table = "posts")]
pub struct Post {
    #[georm(id, defaultable)]
    pub id: i32,                    // Auto-generated serial
    pub title: String,
    #[georm(defaultable)]
    pub published: bool,            // Database default (false)
    #[georm(defaultable)]
    pub created_at: chrono::DateTime<chrono::Utc>, // DEFAULT NOW()
}

// Use the generated companion struct
let post_default = PostDefault {
    id: None,                       // Let database auto-generate
    title: "My Post".to_string(),
    published: None,                // Use database default
    created_at: None,               // Use database default
};
let created_post = post_default.create(pool).await?;

Foreign One-to-One Relationships

• Enhanced relationship support: Complete support for one-to-one relationships with foreign keys
• Automatic method generation: Generates getter methods for related entities

🚀 Performance & Reliability

Atomic Upsert Operations

• Race condition elimination: Replaced two-query create_or_update with single atomic PostgreSQL upsert
• Performance improvement: Reduced database round trips from 2-3 queries to 1
• PostgreSQL ON CONFLICT: Uses native PostgreSQL INSERT ... ON CONFLICT ... DO UPDATE SET for reliability

Modern Rust Support

• Rust 1.86 & Edition 2024: Updated to the latest Rust version and edition
• Dependency updates: Updated SQLx to 0.8.6 and other dependencies
• Security fixes: Updated tokio to address RUSTSEC-2025-0023

📚 Documentation & Examples

Comprehensive Documentation Rewrite

• Complete README overhaul: Comprehensive guide covering all features with examples
• Enhanced API documentation: Detailed method documentation with usage patterns
• Performance characteristics: Documentation of zero-cost abstractions and compile-time guarantees

Real-World Example

• PostgreSQL example: Full-featured example with user management, comments, and follower relationships
• Interactive CLI: Demonstrates CRUD operations and relationship handling
• Database migrations: Complete schema setup and migration examples

🛠️ Developer Experience

Improved Development Environment

• Devenv migration: Switched from Nix flakes to devenv for better developer experience
• Modular code organization: Split trait implementations into separate modules by operation type
• Enhanced tooling: Better IDE support and development workflow

Breaking Changes

⚠️ Important: This release includes breaking changes to the create_or_update method implementation. The method signature remains the same, but the implementation now uses atomic upserts instead of separate find/create/update operations.

Migration Guide

From 0.1.x to 0.2.0

1. Update your Cargo.toml:

[dependencies]
georm = "0.2.0"
sqlx = { version = "0.8.6", features = ["runtime-tokio-rustls", "postgres", "macros"] }

2. Review create_or_update usage: The method now uses atomic upserts, which may have different error handling characteristics.

3. Consider using defaultable fields: If you have entities with database defaults, consider marking fields with #[georm(defaultable)] for easier creation.

What's Next?

Looking ahead to future releases:

• Transaction Support (high priority)
• Composite Key Relationships: Relationship support for entities with composite primary keys
• Multi-Database Support: MySQL and SQLite support
• Field-Based Queries: Generate find_by_{field} methods

Acknowledgments

This release represents a significant step forward in Georm's capabilities. Special thanks to the SQLx team for their excellent foundation that makes Georm's compile-time safety possible.

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Full Changelog: 0.1.1...0.2.0