LambdaModel - Type-Safe Lambda Queries

The Future of Salesforce ORM: Full type inference, closure variables, and IntelliSense support.

Overview

LambdaModel provides a lambda-based query interface with:

• ✅ Full TypeScript type inference - IntelliSense for all fields
• ✅ Closure variable support - Use variables from outer scope
• ✅ Type-safe field selection - Compiler catches typos
• ✅ Subquery support - Query relationships with closures
• ✅ Clean syntax - Fluent, chainable API

View on GitHub

Quick Example

// Define your model
interface AccountData extends ModelData {
  Id: string;
  Name: string;
  Industry: string;
  AnnualRevenue: number;
}

class Account extends LambdaModel<AccountData> {
  protected static objectName = 'Account';
}

// Query with full type safety and closure support
const industry = 'Technology';
const minRevenue = 1000000;

const accounts = await Account
  .select(x => ({
    Id: x.Id,           // ✓ IntelliSense works!
    Name: x.Name,       // ✓ Typos caught at compile time
    Industry: x.Industry
  }))
  .where(x => x.Industry === industry && x.AnnualRevenue > minRevenue)  // ✓ Closures work!
  .orderBy(x => x.AnnualRevenue, 'DESC')
  .limit(10)
  .get();

Table of Contents

• Getting Started
• Field Selection
• WHERE Clauses
• Ordering & Pagination
• Relationships & Subqueries
• count() and exists()
• Migration Guide

Getting Started

Define Your Model

import { LambdaModel, ModelData, RelationshipArray } from 'javascript-salesforce-connector';

interface ContactData extends ModelData {
  Id: string;
  Name: string;
  Email: string;
  Title: string;
}

interface AccountData extends ModelData {
  Id: string;
  Name: string;
  Industry: string;
  AnnualRevenue: number;
  Contacts: RelationshipArray<ContactData>;
}

class Account extends LambdaModel<AccountData> {
  protected static objectName = 'Account';

  // Define relationship getter for runtime access
  get Contacts(): RelationshipArray<ContactData> {
    return (this.get("Contacts") as any) || [];
  }
}

Basic Query

const accounts = await Account
  .select(x => ({
    Id: x.Id,
    Name: x.Name
  }))
  .get();

// Type: { Id: string, Name: string }[]

Field Selection

Simple Fields

const results = await Account
  .select(x => ({
    Id: x.Id,
    Name: x.Name,
    Industry: x.Industry
  }))
  .get();

Nested Fields

const results = await Account
  .select(x => ({
    Name: x.Name,
    Street: x.BillingAddress.Street,
    City: x.BillingAddress.City
  }))
  .get();

Single Field

const names = await Account
  .select(x => ({ Name: x.Name }))
  .get();

// Type: { Name: string }[]

WHERE Clauses

Literal Values

// Strings
await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.Industry === 'Technology')
  .get();

// Numbers
await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.AnnualRevenue > 1000000)
  .get();

// Booleans
await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.IsActive === true)
  .get();

Closure Variables

Simple variables:

const industry = 'Technology';
const minRevenue = 1000000;

const accounts = await Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .where(x => x.Industry === industry && x.AnnualRevenue > minRevenue)
  .get();

Object properties:

const config = {
  industry: 'Technology',
  minRevenue: 1000000
};

const accounts = await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.Industry === config.industry)
  .get();

Nested properties:

const filters = {
  account: {
    criteria: {
      industry: 'Technology'
    }
  }
};

const accounts = await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.Industry === filters.account.criteria.industry)
  .get();

String Methods

const searchTerm = 'Tech';

// LIKE '%Tech%'
await Account
  .select(x => ({ Name: x.Name }))
  .where(x => x.Name.includes(searchTerm))
  .get();

// LIKE 'Tech%'
await Account
  .select(x => ({ Name: x.Name }))
  .where(x => x.Name.startsWith(searchTerm))
  .get();

// LIKE '%Tech'
await Account
  .select(x => ({ Name: x.Name }))
  .where(x => x.Name.endsWith(searchTerm))
  .get();

Operators

const results = await Account
  .select(x => ({ Id: x.Id }))
  .where(x =>
    x.AnnualRevenue > 1000000 &&      // >
    x.AnnualRevenue <= 5000000 &&     // <=
    x.NumberOfEmployees >= 100 &&     // >=
    x.Rating !== 'Cold'               // !=
  )
  .get();

Complex Conditions

// AND and OR
const results = await Account
  .select(x => ({ Id: x.Id }))
  .where(x =>
    (x.Industry === 'Technology' || x.Industry === 'Finance') &&
    x.AnnualRevenue > 1000000
  )
  .get();

// Multiple WHERE (combined with AND)
const results = await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.Industry === 'Technology')
  .where(x => x.AnnualRevenue > 1000000)
  .get();

Ordering & Pagination

Order By

const sorted = await Account
  .select(x => ({ Name: x.Name, Revenue: x.AnnualRevenue }))
  .orderBy(x => x.AnnualRevenue, 'DESC')
  .get();

Limit & Offset

const paginated = await Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .limit(20)
  .offset(40)
  .get();

Paginate Helper

const { records, totalSize, hasNextPage } = await Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .where(x => x.Industry === 'Technology')
  .paginate(3, 20);  // Page 3, 20 per page

console.log(`Total: ${totalSize}, Has next: ${hasNextPage}`);

First Record

const account = await Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .where(x => x.Industry === 'Technology')
  .first();

// Type: { Id: string, Name: string } | null

Relationships & Subqueries

Basic Subquery

const accounts = await Account
  .select(x => ({
    Name: x.Name,
    Contacts: x.Contacts.select(c => ({
      Name: c.Name,
      Email: c.Email
    }))
  }))
  .get();

Subquery with WHERE (Closure Support!)

const activeStatus = true;

const accounts = await Account
  .select(x => ({
    Name: x.Name,
    ActiveContacts: x.Contacts
      .select(c => ({ Name: c.Name }))
      .where(c => c.Active__c === activeStatus)  // ✓ Closure works!
  }))
  .get();

Complex Subquery Filters

const config = {
  contacts: {
    active: true,
    title: 'VP Sales'
  }
};

const accounts = await Account
  .select(x => ({
    Name: x.Name,
    FilteredContacts: x.Contacts
      .select(c => ({ Name: c.Name, Title: c.Title }))
      .where(c =>
        c.Active__c === config.contacts.active &&
        c.Title === config.contacts.title
      )
  }))
  .get();

Subquery Ordering & Limiting

const accounts = await Account
  .select(x => ({
    Name: x.Name,
    TopContacts: x.Contacts
      .select(c => ({ Name: c.Name }))
      .orderBy(c => c.CreatedDate, 'DESC')
      .limit(5)
  }))
  .get();

Multiple Subqueries

const activeStatus = true;
const minAmount = 50000;

const accounts = await Account
  .select(x => ({
    Name: x.Name,
    ActiveContacts: x.Contacts
      .select(c => ({ Name: c.Name }))
      .where(c => c.Active__c === activeStatus),
    BigOpportunities: x.Opportunities
      .select(o => ({ Name: o.Name, Amount: o.Amount }))
      .where(o => o.Amount > minAmount)
  }))
  .get();

count() and exists()

Count with Closure

// Count all
const total = await Account.count();

// Count with condition
const industry = 'Technology';
const techCount = await Account.count(x => x.Industry === industry);

// Complex condition
const count = await Account.count(x =>
  x.Industry === 'Technology' && x.AnnualRevenue > 1000000
);

Exists with Closure

const companyName = 'Acme Corp';
const exists = await Account.exists(x => x.Name === companyName);

if (exists) {
  console.log('Found!');
}

Migration Guide

From QueryBuilder (Old) to LambdaModel (New)

Before (deprecated):

import { Model } from 'javascript-salesforce-connector';

class Account extends Model<AccountData> {
  protected static objectName = 'Account';
}

// String-based queries
const industry = 'Technology';
const accounts = await Account
  .select('Id', 'Name', 'Industry')
  .where('Industry', industry)
  .where('AnnualRevenue', '>', 1000000)
  .get();

After (recommended):

import { LambdaModel } from 'javascript-salesforce-connector';

class Account extends LambdaModel<AccountData> {
  protected static objectName = 'Account';
}

// Lambda-based queries
const industry = 'Technology';
const accounts = await Account
  .select(x => ({
    Id: x.Id,
    Name: x.Name,
    Industry: x.Industry
  }))
  .where(x => x.Industry === industry && x.AnnualRevenue > 1000000)
  .get();

Benefits of Migration

1. Type Safety: Catch typos at compile time
2. IntelliSense: Field suggestions in your IDE
3. Closure Support: Use variables naturally
4. Cleaner Code: More readable lambda syntax
5. Future Proof: Will be the default in v2.0

What's Changing in v2.0

• LambdaModel → Model (rename)
• Current Model → Removed
• QueryBuilder → Removed
• Lambda syntax will be the only way

Start migrating now!

Debug Queries

Use toSOQL() to see the generated query:

const query = Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .where(x => x.Industry === 'Technology')
  .orderBy(x => x.AnnualRevenue, 'DESC')
  .limit(10);

console.log(query.toSOQL());
// Output: SELECT Id, Name FROM Account WHERE Industry = 'Technology' ORDER BY AnnualRevenue DESC LIMIT 10

API Reference

LambdaModel Static Methods

Method	Description	Example
select(fn)	Select fields with type inference	Account.select(x => ({ Id: x.Id }))
count(fn?)	Count records	Account.count(x => x.IsActive)
exists(fn)	Check existence	Account.exists(x => x.Name === 'Acme')
find(id)	Find by ID	Account.find('001...')
create(data)	Create record	Account.create({ Name: 'Acme' })

TypedQueryBuilder Methods

Method	Description	Example
where(fn)	Filter with closures	.where(x => x.Industry === industry)
orderBy(fn, dir)	Sort results	.orderBy(x => x.Name, 'ASC')
limit(n)	Limit results	.limit(10)
offset(n)	Skip records	.offset(20)
get()	Execute query	.get()
first()	Get first result	.first()
paginate(page, size)	Paginated results	.paginate(1, 20)
toSOQL()	Get SOQL string	.toSOQL()

Best Practices

1. Always Use Types

interface AccountData extends ModelData {
  Id: string;
  Name: string;
  Industry: string;
}

class Account extends LambdaModel<AccountData> {
  protected static objectName = 'Account';
}

2. Select Only What You Need

// ✓ Good
const accounts = await Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .get();

// ✗ Avoid
const accounts = await Account
  .select(x => ({
    // ... 30 fields you don't need
  }))
  .get();

3. Use Closures for Dynamic Queries

const filters = getUserFilters();

const accounts = await Account
  .select(x => ({ Id: x.Id, Name: x.Name }))
  .where(x => x.Industry === filters.industry)
  .get();

4. Leverage IntelliSense

Let your IDE autocomplete field names - that's the power of lambda syntax!

5. Use first() for Single Records

const account = await Account
  .select(x => ({ Id: x.Id }))
  .where(x => x.ExternalId__c === id)
  .first();

Common Patterns

Search Pattern

function searchAccounts(searchTerm: string) {
  return Account
    .select(x => ({ Id: x.Id, Name: x.Name }))
    .where(x => x.Name.includes(searchTerm))
    .limit(50)
    .get();
}

Filtered List Pattern

interface AccountFilters {
  industry?: string;
  minRevenue?: number;
  isActive?: boolean;
}

async function getFilteredAccounts(filters: AccountFilters) {
  let query = Account.select(x => ({
    Id: x.Id,
    Name: x.Name,
    Industry: x.Industry
  }));

  if (filters.industry) {
    query = query.where(x => x.Industry === filters.industry);
  }

  if (filters.minRevenue) {
    query = query.where(x => x.AnnualRevenue > filters.minRevenue);
  }

  if (filters.isActive !== undefined) {
    query = query.where(x => x.IsActive === filters.isActive);
  }

  return query.get();
}

Master-Detail Query Pattern

async function getAccountsWithContacts(industry: string) {
  return Account
    .select(x => ({
      Id: x.Id,
      Name: x.Name,
      PrimaryContacts: x.Contacts
        .select(c => ({
          Name: c.Name,
          Email: c.Email,
          Phone: c.Phone
        }))
        .where(c => c.IsPrimary__c === true)
        .limit(1)
    }))
    .where(x => x.Industry === industry)
    .get();
}

Learn More

• Main Documentation
• GitHub Repository
• NPM Package