Skip to main content

Eager Loading & Relations

EntityTS eliminates the N+1 query problem by batch-loading related entities in single efficient queries using the LINQ .include() and .thenInclude() syntax.

LINQ .include() Syntax​

1. Strongly-Typed Lambda Selectors​

// Eager load related posts for each user
const usersWithPosts = await db.users.include(u => u.posts).toList();

2. Multi-Level Chaining with .thenInclude()​

// Eager load nested relations (User -> Posts -> Comments -> Author)
const blogFeed = await db.users
  .include(u => u.posts)
  .thenInclude(p => p.comments)
  .include(u => u.profile)
  .where(u => u.isActive, '=', true)
  .toList();

3. Property Name String Syntax​

// Eager load via property name key
const usersWithProfile = await db.users.include('profile').include('posts').toList();

Lazy / On-Demand Loading​

For workflows where related data should only be loaded when explicitly requested:

const user = await db.users.find(1);

// Programmatically fetch relation when needed
const posts = await db.users.fetchRelation(user, 'posts');