mikro-orm/mikro-orm
Mikro Orm
Mikro-ORM is a TypeScript-based object-relational mapping system that provides a unified persistence layer for Node.js applications. It translates TypeScript entities into relational or document-based database schemas, supporting a variety of engines including PostgreSQL, MySQL, MariaDB, MS SQL Server, SQLite, and MongoDB.
The project implements the data mapper pattern to decouple in-memory domain models from the database persistence layer. It utilizes a unit of work pattern to track entity changes in memory and commit them in a single coordinated database transaction.
The library covers comprehensive data storage and synchronization capabilities, including type-safe query building, versioned schema migrations, and request-scoped state management. It provides advanced data modeling for entity inheritance and polymorphic relations, along with tools for query performance monitoring, result caching, and global data filtering.
Command-line utilities are included for managing database migrations, seeding data, and exporting entity definitions from existing schemas.
Features
- Object-Relational Mappers - Implements a full-featured object-relational mapper that decouples domain models from the persistence layer.
- Data Mappers - Implements the data mapper pattern to decouple in-memory domain models from the database persistence layer.
- Database Mapping - Provides a unified mapping layer compatible with both relational and document-based database engines.
- Relational Persistence Layers - Provides a relational persistence layer that manages data storage using schemas and object-relational mapping.
- Database Adapters - Implements a standardized adapter layer to decouple application logic from multiple supported database engines.
- Atomic Transactions - Groups multiple data operations into a single atomic unit to ensure database consistency.
- Entity CRUD Management - Provides fundamental CRUD capabilities for inserting, updating, deleting, and retrieving entities.
- Identity Maps - Maintains an identity map to ensure each database record is represented by a single unique object instance.
- Fluent Query Builders - Ships a fluent, method-chaining interface for constructing type-safe database queries.
- State Change Tracking - Monitors modifications to in-memory objects to ensure accurate persistence during database synchronization.
- Persistence Layers - Provides a unified persistence interface supporting multiple database engines including PostgreSQL, MySQL, and MongoDB.
- Schema Definitions - Provides a declarative system for defining data object structures using schemas and decorators.
- Type-Safe Query Builders - Offers a type-safe query builder with compile-time validation, relational population, and sorting.
- TypeScript Database Modeling - Allows defining complex data structures and relationships using TypeScript classes to mirror relational or document databases.
- Metadata Mapping - Uses decorators and schema definitions to declaratively map class properties to database columns.
- Unit of Work Patterns - Implements a unit of work pattern to track entity changes in memory and commit them in one coordinated transaction.
- Request-Scoped State - Ties database state management to the lifecycle of a single execution request to prevent user data leakage.
- Identity Maps - Isolates identity maps to individual web requests to ensure data consistency and prevent leakage.
- Data Loading Optimizations - Offers loading strategies and partial field fetching to reduce memory usage and improve response times.
- Database Schema Migrations - Automates the application of versioned updates to keep database schemas in sync with application code.
- Database Migration Management - Ships a comprehensive system for tracking and applying schema changes using versioned migration files.
- Database Migration Tools - Provides utilities for generating and executing versioned schema changes to keep the database in sync.
- Database Schema Constraints - Enforces data integrity across different engines through defined check constraints, unique keys, and foreign keys.
- Database Schema Managers - Provides declarative tools for defining and managing database structures based on entity models.
- Global Data Filters - Provides a mechanism to restrict returned entities using global or relation-specific filters for multi-tenancy and soft-delete logic.
- Optimistic Locking - Prevents concurrent update conflicts by checking a version column before committing changes.
- Polymorphic Data Modeling - Supports advanced data modeling including entity inheritance and polymorphic relations.
- Schema Migrations - Implements a system for automating database structure evolution via versioned migrations.
- Database ORMs - ORM based on Data Mapper and Unit of Work patterns.
- Database Tools - Object-relational mapper with unit of work support.
- Datenbanken - TypeScript ORM with data mapper and identity map.
- Object Relational Mappers - TypeScript ORM based on Data Mapper patterns.
- Search and Databases - Implements Data Mapper and Unit of Work patterns.
