Query Scopes

What are Query Scopes?

Query scopes are reusable query constraints that you can define in your models. They allow you to encapsulate common query logic and chain it with other query methods for clean, readable code.

Real-world analogy: Query scopes are like preset filters on a camera. Instead of manually adjusting settings every time (ISO, aperture, shutter speed), you have presets like “Portrait,” “Landscape,” or “Night Mode” that apply multiple settings at once. Similarly, scopes apply multiple query conditions with a single method call.

Basic Scopes

Defining Scopes

// models/Post.js
class Post extends Model {
  // Simple scope - no parameters
  static scopePublished(query) {
    return query.where('is_published', true);
  }
  
  // Scope with parameters
  static scopeOfType(query, type) {
    return query.where('type', type);
  }
  
  // Complex scope with multiple conditions
  static scopePopular(query, threshold = 100) {
    return query
      .where('views', '>', threshold)
      .where('likes', '>', 10)
      .orderBy('views', 'desc');
  }
  
  // Date-based scope
  static scopeRecent(query, days = 7) {
    const date = new Date();
    date.setDate(date.getDate() - days);
    return query.where('created_at', '>', date);
  }
}

Using Scopes

// Simple scope usage
const publishedPosts = await Post.query().published().get();

// Scope with parameters
const articles = await Post.query().ofType('article').get();

// Chaining multiple scopes
const popularRecentPosts = await Post.query()
  .published()
  .popular(500)
  .recent(30)
  .get();

// Combining scopes with other query methods
const results = await Post.query()
  .published()
  .ofType('tutorial')
  .where('author_id', userId)
  .orderBy('created_at', 'desc')
  .limit(10)
  .get();

Scope Naming: Scope methods are automatically available without the scope prefix. scopePublished becomes published(), scopeOfType becomes ofType().

Advanced Scope Patterns

Conditional Scopes

class User extends Model {
  static scopeActive(query, isActive = true) {
    return query.where('is_active', isActive);
  }
  
  static scopeByRole(query, roles) {
    if (Array.isArray(roles)) {
      return query.whereIn('role', roles);
    }
    return query.where('role', roles);
  }
  
  static scopeSearch(query, term) {
    if (!term) return query;
    
    return query.where((q) => {
      q.where('name', 'like', `%${term}%`)
       .orWhere('email', 'like', `%${term}%`)
       .orWhere('username', 'like', `%${term}%`);
    });
  }
  
  static scopeWithinDateRange(query, startDate, endDate) {
    if (startDate) {
      query = query.where('created_at', '>=', startDate);
    }
    
    if (endDate) {
      query = query.where('created_at', '<=', endDate);
    }
    
    return query;
  }
}

// Usage
const users = await User.query()
  .active()
  .byRole(['admin', 'editor'])
  .search('john')
  .withinDateRange(new Date('2023-01-01'), new Date('2023-12-31'))
  .get();

Relationship Scopes

class Post extends Model {
  static scopeByAuthor(query, authorId) {
    return query.where('user_id', authorId);
  }
  
  static scopeWithAuthor(query, authorName) {
    return query.whereHas('author', (authorQuery) => {
      authorQuery.where('name', 'like', `%${authorName}%`);
    });
  }
  
  static scopeWithComments(query, minComments = 1) {
    return query.has('comments', '>=', minComments);
  }
  
  static scopeWithoutComments(query) {
    return query.doesntHave('comments');
  }
  
  static scopeInCategory(query, categorySlug) {
    return query.whereHas('category', (categoryQuery) => {
      categoryQuery.where('slug', categorySlug);
    });
  }
  
  static scopeWithTags(query, tags) {
    return query.whereHas('tags', (tagQuery) => {
      if (Array.isArray(tags)) {
        tagQuery.whereIn('name', tags);
      } else {
        tagQuery.where('name', tags);
      }
    });
  }
}

// Usage
const posts = await Post.query()
  .published()
  .withAuthor('John')
  .withComments(5)
  .inCategory('technology')
  .withTags(['javascript', 'nodejs'])
  .get();

Aggregation Scopes

class Order extends Model {
  static scopeByStatus(query, status) {
    return query.where('status', status);
  }
  
  static scopeByDateRange(query, startDate, endDate) {
    return query.whereBetween('created_at', [startDate, endDate]);
  }
  
  static scopeWithMinTotal(query, minAmount) {
    return query.where('total', '>=', minAmount);
  }
  
  static scopeGroupedByStatus(query) {
    return query
      .select('status')
      .selectRaw('COUNT(*) as count')
      .selectRaw('SUM(total) as total_amount')
      .selectRaw('AVG(total) as average_amount')
      .groupBy('status');
  }
  
  static scopeMonthlyStats(query, year) {
    return query
      .selectRaw('MONTH(created_at) as month')
      .selectRaw('COUNT(*) as order_count')
      .selectRaw('SUM(total) as revenue')
      .whereYear('created_at', year)
      .groupBy('month')
      .orderBy('month');
  }
}

// Usage
const stats = await Order.query()
  .byStatus('completed')
  .byDateRange(startDate, endDate)
  .monthlyStats(2023)
  .get();

Dynamic Scopes

Parameterized Dynamic Scopes

class Product extends Model {
  static scopeInPriceRange(query, min, max) {
    if (min !== undefined) {
      query = query.where('price', '>=', min);
    }
    
    if (max !== undefined) {
      query = query.where('price', '<=', max);
    }
    
    return query;
  }
  
  static scopeWithFilters(query, filters = {}) {
    // Category filter
    if (filters.category) {
      query = query.where('category_id', filters.category);
    }
    
    // Brand filter
    if (filters.brand) {
      query = query.where('brand', filters.brand);
    }
    
    // Price range filter
    if (filters.minPrice || filters.maxPrice) {
      query = query.inPriceRange(filters.minPrice, filters.maxPrice);
    }
    
    // In stock filter
    if (filters.inStock) {
      query = query.where('stock_quantity', '>', 0);
    }
    
    // Rating filter
    if (filters.minRating) {
      query = query.where('average_rating', '>=', filters.minRating);
    }
    
    // Search filter
    if (filters.search) {
      query = query.where((q) => {
        q.where('name', 'like', `%${filters.search}%`)
         .orWhere('description', 'like', `%${filters.search}%`);
      });
    }
    
    return query;
  }
  
  static scopeSortBy(query, sortBy, direction = 'asc') {
    const allowedSorts = ['name', 'price', 'created_at', 'average_rating'];
    
    if (allowedSorts.includes(sortBy)) {
      return query.orderBy(sortBy, direction);
    }
    
    return query.orderBy('created_at', 'desc');
  }
}

// Usage
const products = await Product.query()
  .withFilters({
    category: 1,
    minPrice: 10,
    maxPrice: 100,
    inStock: true,
    minRating: 4,
    search: 'laptop',
  })
  .sortBy('price', 'asc')
  .paginate(1, 20);

Builder Pattern Scopes

class User extends Model {
  static scopeFilter(query, callback) {
    return callback(new UserFilterBuilder(query));
  }
}

class UserFilterBuilder {
  constructor(query) {
    this.query = query;
  }
  
  active(isActive = true) {
    this.query = this.query.where('is_active', isActive);
    return this;
  }
  
  role(roles) {
    if (Array.isArray(roles)) {
      this.query = this.query.whereIn('role', roles);
    } else {
      this.query = this.query.where('role', roles);
    }
    return this;
  }
  
  search(term) {
    if (term) {
      this.query = this.query.where((q) => {
        q.where('name', 'like', `%${term}%`)
         .orWhere('email', 'like', `%${term}%`);
      });
    }
    return this;
  }
  
  createdAfter(date) {
    this.query = this.query.where('created_at', '>', date);
    return this;
  }
  
  createdBefore(date) {
    this.query = this.query.where('created_at', '<', date);
    return this;
  }
  
  withPosts(minPosts = 1) {
    this.query = this.query.has('posts', '>=', minPosts);
    return this;
  }
  
  // Return the final query
  build() {
    return this.query;
  }
}

// Usage
const users = await User.query()
  .filter((filter) => {
    return filter
      .active()
      .role(['admin', 'editor'])
      .search('john')
      .createdAfter(new Date('2023-01-01'))
      .withPosts(5)
      .build();
  })
  .get();

Global Scopes

Automatic Scopes

// Global scope that applies to all queries
class SoftDeleteScope {
  apply(query, model) {
    if (model.softDeletes) {
      return query.whereNull(`${model.table}.deleted_at`);
    }
    return query;
  }
}

class TenantScope {
  constructor(tenantId) {
    this.tenantId = tenantId;
  }
  
  apply(query, model) {
    if (model.hasColumn('tenant_id')) {
      return query.where(`${model.table}.tenant_id`, this.tenantId);
    }
    return query;
  }
}

// Apply global scopes
class User extends Model {
  static softDeletes = true;
  
  static boot() {
    super.boot();
    
    // Add global scopes
    this.addGlobalScope(new SoftDeleteScope());
    this.addGlobalScope(new TenantScope(getCurrentTenantId()));
  }
  
  // Method to remove global scopes
  static withoutGlobalScopes() {
    return this.query().withoutGlobalScopes();
  }
  
  static withTrashed() {
    return this.query().withoutGlobalScope(SoftDeleteScope);
  }
}

Scope Composition

Combining Scopes

class Post extends Model {
  // Base scopes
  static scopePublished(query) {
    return query.where('is_published', true);
  }
  
  static scopeFeatured(query) {
    return query.where('is_featured', true);
  }
  
  static scopeRecent(query, days = 7) {
    const date = new Date();
    date.setDate(date.getDate() - days);
    return query.where('created_at', '>', date);
  }
  
  // Composite scopes
  static scopeFeaturedAndRecent(query, days = 7) {
    return query.featured().recent(days);
  }
  
  static scopePublishedAndPopular(query, minViews = 1000) {
    return query
      .published()
      .where('views', '>', minViews)
      .orderBy('views', 'desc');
  }
  
  static scopeHomepageContent(query) {
    return query
      .published()
      .featured()
      .recent(30)
      .orderBy('featured_at', 'desc')
      .limit(5);
  }
}

// Usage
const homepagePosts = await Post.query().homepageContent().get();

Scope Inheritance

// Base model with common scopes
class BaseModel extends Model {
  static scopeActive(query) {
    return query.where('is_active', true);
  }
  
  static scopeCreatedBetween(query, startDate, endDate) {
    return query.whereBetween('created_at', [startDate, endDate]);
  }
  
  static scopeOrderByLatest(query) {
    return query.orderBy('created_at', 'desc');
  }
}

// Inherit scopes
class User extends BaseModel {
  // User-specific scopes
  static scopeVerified(query) {
    return query.whereNotNull('email_verified_at');
  }
  
  static scopeByRole(query, role) {
    return query.where('role', role);
  }
}

class Post extends BaseModel {
  // Post-specific scopes
  static scopePublished(query) {
    return query.where('is_published', true);
  }
  
  static scopeByAuthor(query, authorId) {
    return query.where('user_id', authorId);
  }
}

// Both models can use inherited scopes
const activeUsers = await User.query().active().get();
const recentPosts = await Post.query().active().orderByLatest().get();

Testing Scopes

Unit Testing Scopes

// test/scopes/PostScopes.test.js
const Post = require('../../models/Post');

describe('Post Scopes', () => {
  beforeEach(async () => {
    // Clear and seed test data
    await Post.query().delete();
    
    await Post.create({
      title: 'Published Post',
      is_published: true,
      views: 150,
      created_at: new Date(),
    });
    
    await Post.create({
      title: 'Draft Post',
      is_published: false,
      views: 50,
      created_at: new Date(),
    });
    
    await Post.create({
      title: 'Popular Post',
      is_published: true,
      views: 1500,
      created_at: new Date(),
    });
  });
  
  describe('published scope', () => {
    test('returns only published posts', async () => {
      const posts = await Post.query().published().get();
      
      expect(posts).toHaveLength(2);
      posts.forEach(post => {
        expect(post.is_published).toBe(true);
      });
    });
  });
  
  describe('popular scope', () => {
    test('returns posts with views above threshold', async () => {
      const posts = await Post.query().popular(100).get();
      
      expect(posts).toHaveLength(2);
      posts.forEach(post => {
        expect(post.views).toBeGreaterThan(100);
      });
    });
    
    test('uses default threshold when not provided', async () => {
      const posts = await Post.query().popular().get();
      
      posts.forEach(post => {
        expect(post.views).toBeGreaterThan(100);
      });
    });
  });
  
  describe('scope chaining', () => {
    test('can chain multiple scopes', async () => {
      const posts = await Post.query()
        .published()
        .popular(100)
        .get();
      
      posts.forEach(post => {
        expect(post.is_published).toBe(true);
        expect(post.views).toBeGreaterThan(100);
      });
    });
  });
});

Integration Testing

// test/integration/PostFiltering.test.js
describe('Post Filtering Integration', () => {
  test('complex filtering scenario', async () => {
    // Create test data
    const author = await User.create({
      name: 'Test Author',
      email: 'author@test.com',
    });
    
    const category = await Category.create({
      name: 'Technology',
      slug: 'technology',
    });
    
    const post = await Post.create({
      title: 'JavaScript Tutorial',
      content: 'Learn JavaScript...',
      is_published: true,
      views: 500,
      user_id: author.id,
      category_id: category.id,
    });
    
    // Test complex scope chain
    const results = await Post.query()
      .published()
      .popular(100)
      .byAuthor(author.id)
      .inCategory('technology')
      .get();
    
    expect(results).toHaveLength(1);
    expect(results[0].id).toBe(post.id);
  });
});

Performance Optimization

Efficient Scopes

class Post extends Model {
  // ✅ Good - uses indexes
  static scopePublished(query) {
    return query.where('is_published', true); // Assumes index on is_published
  }
  
  // ✅ Good - limits results early
  static scopeLatest(query, limit = 10) {
    return query
      .orderBy('created_at', 'desc')
      .limit(limit);
  }
  
  // ✅ Good - uses specific selects
  static scopeForListing(query) {
    return query.select([
      'id', 'title', 'excerpt', 'created_at', 'user_id'
    ]);
  }
  
  // ❌ Avoid - expensive operations
  static scopeWithExpensiveCalculation(query) {
    return query.selectRaw(`
      *,
      (SELECT COUNT(*) FROM comments WHERE post_id = posts.id) as comment_count,
      (SELECT AVG(rating) FROM reviews WHERE post_id = posts.id) as avg_rating
    `);
  }
}

Cached Scopes

class Post extends Model {
  static scopePopularCached(query, threshold = 100) {
    const cacheKey = `popular_posts_${threshold}`;
    
    // Check cache first
    const cached = cache.get(cacheKey);
    if (cached) {
      return query.whereIn('id', cached);
    }
    
    // If not cached, build query and cache result
    return query
      .where('views', '>', threshold)
      .orderBy('views', 'desc')
      .tap(async (results) => {
        const ids = results.map(post => post.id);
        cache.put(cacheKey, ids, 3600); // Cache for 1 hour
      });
  }
}

Best Practices

1. Keep Scopes Focused

// ✅ Good - single responsibility
static scopePublished(query) {
  return query.where('is_published', true);
}

static scopeRecent(query, days = 7) {
  const date = new Date();
  date.setDate(date.getDate() - days);
  return query.where('created_at', '>', date);
}

// ❌ Bad - doing too much
static scopePublishedAndRecentAndPopular(query) {
  return query
    .where('is_published', true)
    .where('created_at', '>', someDate)
    .where('views', '>', 100)
    .orderBy('views', 'desc');
}

2. Use Descriptive Names

// ✅ Good - clear intent
static scopePublished(query) { /* ... */ }
static scopeByAuthor(query, authorId) { /* ... */ }
static scopeWithMinimumViews(query, views) { /* ... */ }

// ❌ Bad - unclear purpose
static scopeFilter1(query) { /* ... */ }
static scopeSpecial(query) { /* ... */ }
static scopeCustom(query, param) { /* ... */ }

3. Handle Parameters Safely

// ✅ Good - validates parameters
static scopeByRole(query, roles) {
  if (!roles) return query;
  
  if (Array.isArray(roles)) {
    return query.whereIn('role', roles);
  }
  
  return query.where('role', roles);
}

// ❌ Bad - no parameter validation
static scopeByRole(query, roles) {
  return query.whereIn('role', roles); // Fails if roles is not array
}

4. Document Complex Scopes

/**
 * Scope for filtering posts by engagement metrics
 * 
 * @param {QueryBuilder} query
 * @param {Object} options
 * @param {number} options.minViews - Minimum view count
 * @param {number} options.minLikes - Minimum like count
 * @param {number} options.minComments - Minimum comment count
 * @param {number} options.days - Days to look back (default: 30)
 */
static scopeHighEngagement(query, options = {}) {
  const {
    minViews = 1000,
    minLikes = 50,
    minComments = 10,
    days = 30
  } = options;
  
  const date = new Date();
  date.setDate(date.getDate() - days);
  
  return query
    .where('views', '>=', minViews)
    .where('likes', '>=', minLikes)
    .has('comments', '>=', minComments)
    .where('created_at', '>', date);
}

What are Query Scopes?

Basic Scopes

Defining Scopes

Using Scopes

Advanced Scope Patterns

Conditional Scopes

Relationship Scopes

Aggregation Scopes

Dynamic Scopes

Parameterized Dynamic Scopes

Builder Pattern Scopes

Global Scopes

Automatic Scopes

Scope Composition

Combining Scopes

Scope Inheritance

Testing Scopes

Unit Testing Scopes

Integration Testing

Performance Optimization

Efficient Scopes

Cached Scopes

Best Practices

1. Keep Scopes Focused

2. Use Descriptive Names

3. Handle Parameters Safely

4. Document Complex Scopes

Next Steps

API Reference

Model Methods

​What are Query Scopes?

​Basic Scopes

​Defining Scopes

​Using Scopes

​Advanced Scope Patterns

​Conditional Scopes

​Relationship Scopes

​Aggregation Scopes

​Dynamic Scopes

​Parameterized Dynamic Scopes

​Builder Pattern Scopes

​Global Scopes

​Automatic Scopes

​Scope Composition

​Combining Scopes

​Scope Inheritance

​Testing Scopes

​Unit Testing Scopes

​Integration Testing

​Performance Optimization

​Efficient Scopes

​Cached Scopes

​Best Practices

​1. Keep Scopes Focused

​2. Use Descriptive Names

​3. Handle Parameters Safely

​4. Document Complex Scopes

​Next Steps

API Reference

Model Methods

What are Query Scopes?

Basic Scopes

Defining Scopes

Using Scopes

Advanced Scope Patterns

Conditional Scopes

Relationship Scopes

Aggregation Scopes

Dynamic Scopes

Parameterized Dynamic Scopes

Builder Pattern Scopes

Global Scopes

Automatic Scopes

Scope Composition

Combining Scopes

Scope Inheritance

Testing Scopes

Unit Testing Scopes

Integration Testing

Performance Optimization

Efficient Scopes

Cached Scopes

Best Practices

1. Keep Scopes Focused

2. Use Descriptive Names

3. Handle Parameters Safely

4. Document Complex Scopes

Next Steps