Documentation Index
Fetch the complete documentation index at: https://docs.ondb.ai/llms.txt
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QueryBuilder provides built-in aggregation methods for counting, summing, averaging, and grouping data.
Basic Aggregations
Count Records
const activeUsers = await client.queryBuilder()
.collection('users')
.whereField('active').equals(true)
.count();
// Returns: number
Sum a Numeric Field
const totalRevenue = await client.queryBuilder()
.collection('orders')
.whereField('status').equals('completed')
.sumBy('amount');
// Returns: number
Calculate Average
const avgPrice = await client.queryBuilder()
.collection('products')
.whereField('category').equals('electronics')
.avgBy('price');
// Returns: number
Find Maximum Value
const highestPrice = await client.queryBuilder()
.collection('products')
.maxBy('price');
// Returns: T | null
Find Minimum Value
const lowestPrice = await client.queryBuilder()
.collection('products')
.minBy('price');
// Returns: T | null
Get Distinct Values
const categories = await client.queryBuilder()
.collection('products')
.distinctBy('category');
// Returns: string[]
Count Distinct Values
const uniqueCategories = await client.queryBuilder()
.collection('products')
.countDistinct('category');
// Returns: number
Grouped Aggregations
Use groupBy() to perform aggregations on groups of records.
Count by Group
// Count users by country
const usersByCountry = await client.queryBuilder()
.collection('users')
.groupBy('country')
.count();
// Returns: { "USA": 150, "UK": 75, "Germany": 50 }
Sum by Group
// Sum order amounts by category
const salesByCategory = await client.queryBuilder()
.collection('orders')
.whereField('status').equals('completed')
.groupBy('category')
.sumBy('amount');
// Returns: { "electronics": 50000, "clothing": 25000 }
Average by Group
// Average rating by product
const avgRatingByProduct = await client.queryBuilder()
.collection('reviews')
.groupBy('productId')
.avgBy('rating');
// Returns: { "prod_1": 4.5, "prod_2": 3.8 }
Max/Min by Group
const maxPriceByCategory = await client.queryBuilder()
.collection('products')
.groupBy('category')
.maxBy('price');
// Returns: { "electronics": 999, "books": 49 }
Nested Field Grouping
GroupBy supports nested field paths:
// Group by nested field
const ordersByRegion = await client.queryBuilder()
.collection('orders')
.groupBy('customer.address.region')
.sumBy('total');
// Returns: { "West": 10000, "East": 8500 }
Combining Aggregations with Filters
// Sum revenue for completed orders in Q4 2024
const q4Revenue = await client.queryBuilder()
.collection('orders')
.find(b => [
b.field('status').equals('completed'),
b.field('createdAt').greaterThanOrEqual('2024-10-01'),
b.field('createdAt').lessThanOrEqual('2024-12-31'),
])
.sumBy('amount');
// Average rating for verified reviews only
const verifiedAvg = await client.queryBuilder()
.collection('reviews')
.whereField('verified').isTrue()
.avgBy('rating');
Aggregation Operators Reference
| Method | Description | Return Type |
|---|
count() | Count matching records | number |
sumBy(field) | Sum values of a field | number |
avgBy(field) | Average values of a field | number |
minBy(field) | Find minimum value | T | null |
maxBy(field) | Find maximum value | T | null |
distinctBy(field) | Get unique values | string[] |
countDistinct(field) | Count unique values | number |
Analytics Dashboard Example
// Dashboard metrics for an e-commerce app
async function getDashboardMetrics() {
const [
totalOrders,
totalRevenue,
avgOrderValue,
ordersByStatus,
revenueByCategory
] = await Promise.all([
client.queryBuilder()
.collection('orders')
.count(),
client.queryBuilder()
.collection('orders')
.whereField('status').equals('completed')
.sumBy('total'),
client.queryBuilder()
.collection('orders')
.whereField('status').equals('completed')
.avgBy('total'),
client.queryBuilder()
.collection('orders')
.groupBy('status')
.count(),
client.queryBuilder()
.collection('orders')
.whereField('status').equals('completed')
.groupBy('category')
.sumBy('total')
]);
return {
totalOrders,
totalRevenue,
avgOrderValue,
ordersByStatus,
revenueByCategory
};
}
Next Steps
JOINs
Relational queries with joinOne and joinMany
Materialized Views
Pre-computed views for complex queries
