lambdaorm

λORM

λORM is an ORM that allows us to perform distributed queries on different database engines.

In λORM, queries are defined using lambda expressions based on a domain model which abstracts us from the infrastructure. For example, in a query you can obtain or modify records from different entities, where some persist in MySQL, others in Postgres, and others in Mongo.

λORM allows you to define different scenarios for the same domain. For example, in one scenario, the infrastructure may consist of distributed instances across SQL Server, MongoDB, and Oracle, while in another scenario it may be a single Postgres instance. This allows the CQRS pattern to be implemented through configuration, without needing to write a single line of code. view example

In addition to being used as a Node.js library, it can be consumed from a command line interface (CLI), a REST service, or a REST service client in other programming languages.

Query Language

Example of a query where orders and their details associated with a customer are obtained:

// Define a query that returns a list of product categories along with the maximum price of each category.
// Filter products based on price and supplier's country or stock availability
// Group products by category and calculate the maximum price
// Map each product to an object with category name and maximum price
// Sort the products by largest price in descending order
const query = (country: string) => Products    
    .filter(p => (p.price > 5 && p.supplier.country == country) || (p.inStock < 3))    
    .having(p => max(p.price) > 50)   
    .map(p => ({ category: p.category.name, largestPrice: max(p.price) }))   
    .sort(p => desc(p.largestPrice));
// Execute the query using the ORM with the specified country parameter
const result = await orm.execute(query, { country: 'ARG' });

more info

Include

The include clause is used, which allows us to bring records from different entities in the same execution:

// Filters orders based on the provided ID and includes details and customers
Orders.filter(p => p.id == id).include(p => [p.details,p.customer])

more info

view: queries select join grouping include inserts bulkInsert update delete repository metadata usage metadata

Schema Configuration

Through the schema, you can define entities, enumerations, indexes, unique keys, default values, constraints, mapping, sources, stages, listeners, etc. The schema can be defined in a JSON or YAML format. Conditions or actions are performed using the same expression language that is used to define queries.

more info

view: definition use expressions environment Variables composite listener multiple stages multiple sources push pull fetch introspect incorporate

Features

• Supports MySQL, MariaDB, PostgresSQL, Oracle, SqlServer, SqlJs and MongoDB.
• Query Language
  • Simple query language based on javascript lambda expressions.
  • Can write the expression as javascript code or as a string
  • DQL, DML and DDL clauses
  • Implicit joins and group by
  • Eager loading using the Include() method.
  • Query expression metadata
• Repositories and custom repositories
• Transactions and distributed transactions
• Schema Configuration
  • Decoupling the domain model from infrastructure
    • Configuration in json or yml formats
    • Definition of mappings between domain and infrastructure
    • Extends entities
    • Environment variables
  • define indices, unique keys and constraints
  • Conditions and actions are based on the expression engine 3xpr
  • Synchronization
• Performance and Optimization
  • BulkInsert
  • High performance queries
  • Connection pooling
• Listeners and subscribers
• TypeScript and JavaScript support
• CLI Support support
• REST API Support
• HTTP Client Support
  • Node Client
  • Kotlin Client (In Progress)
  • Java Client (Coming Soon)
  • C# Client (Coming Soon)
  • Python Client (Coming Soon)

Contributing

Would you like to contribute? Read our contribution guidelines to learn more. There are many ways to help!

Documentation

Full documentation is available in the Wiki.

All Labs

You can access various labs at lambdaorm labs

Related projects

• Lambda ORM CLI
• Lambda ORM Service
• Client Node
• Client Kotlin
• 3xpr