An Object Relational Mapper (ORM) can be a critical tool for any application, and choosing the right ORM at the beginning of your development can make or break a project. An ORM allows you to abstract your database layer from your application logic and interact with your data via objects and methods rather than direct SQL statements. It helps drive faster development, easier application maintenance, and better data consistency. We can build reliable business applications faster, and they’ll still stand the test of time for our clients.
Our project architecture generally includes a Node.js API layer using an ORM for database interactions. We previously used TypeORM in our codebases but moved our architecture to utilize MikroORM. Here are some differences that influenced us to migrate away from TypeORM.
Key Differences Between TypeORM and MikroORM
1. Data Mapping and Architecture
TypeORM
- Can use Active Record or Data Mapper patterns, giving you flexibility in how you define and work with entities.
- Supports both relational databases and document databases (e.g., MongoDB).
- TypeORM is more closely aligned with traditional ORM libraries like Hibernate, with a focus on entity management.
MikroORM
- Primarily uses the Data Mapper pattern.
- MikroORM is designed to be lightweight and performant, focusing on providing a small and efficient codebase.
- It has first-class support for Unit of Work and Identity Map patterns, which are not native to TypeORM.
2. Database Support
TypeORM
- Has broad support for many database solutions including PostgreSQL, MySQL, MariaDB, SQLite, SQL Server, Oracle, and MongoDB.
- Provides extensive database feature support (migrations, transactions, cascading).
MikroORM
- Focused support for relational databases like PostgreSQL, MySQL, MariaDB, SQLite, as well as NoSQL databases like MongoDB.
- Designed to be database-agnostic but with a stronger emphasis on working with SQL databases.
3. Entity Definitions
TypeORM
- Uses decorators heavily to define entities, relations, and other metadata.
- Requires a more declarative approach with explicit configuration of many ORM features.
MikroORM
- Offers multiple ways to define entities: decorators, JavaScript object literals, or a pure JSON configuration.
- Supports automatic discovery of entities, reducing boilerplate and configuration.
4. Performance
TypeORM
- Performance is decent but can be slower compared to more optimized solutions, particularly for larger-scale applications with more complex entity relationships.
- May suffer from N+1 query issues without careful management.
MikroORM
- Designed with performance in mind, offering optimizations like lazy-loading, caching, and efficient Unit of Work implementation.
- Reduces N+1 query problems by utilizing an advanced query builder and automatic batch fetching.
5. Ecosystem and Maturity
TypeORM
- More mature with a larger community and ecosystem, meaning more third-party plugins, integrations, and broader documentation.
- Often chosen for projects that require stability and a well-established codebase.
MikroORM
- Newer but rapidly growing with modern features.
- Focuses on TypeScript-first development, offering better TypeScript support, especially for advanced type safety and inference.
6. Learning Curve and Usability
TypeORM
- Easier for developers familiar with traditional ORMs and decorators.
- Can be more complex due to its broad feature set and flexibility.
MikroORM
- Generally considered easier for TypeScript developers, especially those looking for a more modern, lightweight ORM.
- Simpler API with a focus on performance and efficiency.
7. Data Migrations
TypeORM
- Provides robust migration support out of the box, including schema generation and command-line tools for managing migrations.
MikroORM
- Also offers migrations, but with a more modern and flexible system, allowing automatic schema synchronization and generation.
Overview of MikroORM: Pros & Cons
MikroORM Pros
- Very performant out-of-the-box
- Actively maintained – frequent releases and the Developer responds to issues and bugs in a timely manner.
- Migration generation and management are more intuitive and reliable.
- Stronger type safety than Type ORM
- Provides an Entity Generator to generate entity classes based on an existing database.
- Provides Seeder to seed test data into DB tables.
MikroORM Cons
- Does not support Active Record pattern
- Mikro ORM does not support Active Record pattern and will not because it supports many entity managers in a single context, which would not be possible with Active Record pattern.
- Is a newer and more focused project, so the community is not as large as TypeORM.
- SQL focused
TypeORM Pros
- Versatility: supports both Active Record and Data Mapper patterns.
- Active Record pattern uses a class model and data is manipulated using the methods on the entity model itself.
- Data Mapper pattern uses Repositories to interact with data and uses simpler entity classes.
- Supported on many platforms
- TypeORM documentation states that it “can run in NodeJS, Browser, Cordova, PhoneGap, Ionic, React Native, NativeScript, Expo, and Electron platforms and can be used with TypeScript and JavaScript (ES2021).”
- Supports both relational databases and document databases (e.g., MongoDB).
TypeORM Cons
- Development continues to slow, and releases are infrequent. There are over 2,000 open issues on GitHub, and some are years-old bugs in the codebase that have not been addressed.
- TypeORM is very large in size because all database drivers, CLIs, utilities, functionality, etc., are bundled into a single package.
- Does not have proper type safety; there are several edge cases that can cause a mismatch in object properties between compile/runtime.
- Entity relation hydration pattern can introduce bugs that are difficult to troubleshoot.
- TypeORM does not hydrate entity relationships by default when querying. If a relationship is not specified in the query, the property does not exist on the selected entity. If your query builder does not explicitly join in related entities, then the typescript compiler can think that properties exist on the object that are not present at runtime.
Honorable Mentions
Query Builders like Drizzle, Kysely, and Prisma offer type-safe ways to create SQL queries with varying degrees of relationship management. Still, these libraries are not as feature-rich as full-scale Object Relational Mappers.
Building Your Database Abstraction Layer Strategy
Your project requirements should define what database abstraction layer strategy works best for you. At Soliant, our default choice of TypeScript ORM for our projects is MikroORM. We use MikroORM because it is an actively developed, feature-rich, comprehensive ORM that allows our developers to focus on the code and have most of the database configuration and schema updates handled automatically.
Our clients benefit from this strategy by gaining powerful applications that launch faster and are easy to maintain. Contact our team today to learn more about our development methods and how we help clients solve complex projects with innovative systems.
