Range<Beg, End>

The Range class provides generic range values for representing inclusive or exclusive ranges of ordered data types.

Import:

import { Range } from 'surrealdb';

Source: value/range.ts

Type Parameters

• Beg - The type of the beginning bound
• End - The type of the ending bound

Constructor

new Range(begin, end)

Create a new range value.

Syntax
new Range(begin, end)

Parameters

Examples

// Numeric range [1, 100]
const numericRange = new Range(
    { value: 1, inclusive: true },
    { value: 100, inclusive: true }
);

// Date range
const dateRange = new Range(
    { value: DateTime.parse('2024-01-01'), inclusive: true },
    { value: DateTime.parse('2024-12-31'), inclusive: true }
);

// Half-open range [0, 10)
const halfOpen = new Range(
    { value: 0, inclusive: true },
    { value: 10, inclusive: false }
);

Properties

begin

The beginning bound of the range.

Type: Bound<Beg>

const range = new Range(
    { value: 1, inclusive: true },
    { value: 10, inclusive: true }
);

console.log(range.begin.value); // 1
console.log(range.begin.inclusive); // true

end

The ending bound of the range.

Type: Bound<End>

const range = new Range(
    { value: 1, inclusive: true },
    { value: 10, inclusive: true }
);

console.log(range.end.value); // 10
console.log(range.end.inclusive); // true

Instance Methods

.toString()

Convert to string representation.

Syntax
range.toString()

Returns

string - Range string (e.g., 1..10, 1..=10, 1>..10)

Examples

// Inclusive range [1, 10]
const inclusive = new Range(
    { value: 1, inclusive: true },
    { value: 10, inclusive: true }
);
console.log(inclusive.toString()); // '1..=10'

// Exclusive range (1, 10)
const exclusive = new Range(
    { value: 1, inclusive: false },
    { value: 10, inclusive: false }
);
console.log(exclusive.toString()); // '1>..10'

// Half-open [1, 10)
const halfOpen = new Range(
    { value: 1, inclusive: true },
    { value: 10, inclusive: false }
);
console.log(halfOpen.toString()); // '1..10'

.toJSON()

Serialize for JSON.

Syntax
range.toJSON()

Returns

string - Range string representation

.equals(other)

Check if two ranges are equal.

Syntax
range.equals(other)

Returns

boolean - True if equal

Complete Examples

Numeric Ranges

import { Surreal, Range } from 'surrealdb';

const db = new Surreal();
await db.connect('ws://localhost:8000');

// Define age range for filtering
const adultRange = new Range(
    { value: 18, inclusive: true },
    { value: 120, inclusive: true }
);

// Query with range
const adults = await db.query(`
    SELECT * FROM users 
    WHERE age IN $range
`, {
    range: adultRange
}).collect();

Date Ranges

import { DateTime, Range } from 'surrealdb';

// Define fiscal year
const fiscalYear = new Range(
    { value: DateTime.parse('2024-01-01T00:00:00Z'), inclusive: true },
    { value: DateTime.parse('2024-12-31T23:59:59Z'), inclusive: true }
);

// Query events in date range
const events = await db.query(`
    SELECT * FROM events 
    WHERE date IN $range
`, {
    range: fiscalYear
}).collect();

Price Ranges

import { Decimal, Range } from 'surrealdb';

// Define price range for product filtering
const budgetRange = new Range(
    { value: new Decimal('0'), inclusive: true },
    { value: new Decimal('100'), inclusive: true }
);

const products = await db.query(`
    SELECT * FROM products 
    WHERE price IN $range
`, {
    range: budgetRange
}).collect();

Score Ranges

// Grade ranges
const gradeA = new Range(
    { value: 90, inclusive: true },
    { value: 100, inclusive: true }
);

const gradeB = new Range(
    { value: 80, inclusive: true },
    { value: 89, inclusive: true }
);

// Assign grades
const students = await db.query(`
    SELECT *,
        CASE
            WHEN score IN $gradeA THEN 'A'
            WHEN score IN $gradeB THEN 'B'
            ELSE 'C'
        END AS grade
    FROM students
`, {
    gradeA,
    gradeB
}).collect();

Time-based Filtering

// Recent activity (last 30 days)
const now = DateTime.now();
const thirtyDaysAgo = now.minus(Duration.parse('30d'));

const recentRange = new Range(
    { value: thirtyDaysAgo, inclusive: true },
    { value: now, inclusive: true }
);

const recentActivity = await db.query(`
    SELECT * FROM activity_log 
    WHERE timestamp IN $range
    ORDER BY timestamp DESC
`, {
    range: recentRange
}).collect();

Pagination with ID Ranges

import { RecordId, Range } from 'surrealdb';

// Fetch records in ID range
const idRange = new Range(
    { value: new RecordId('users', 'a'), inclusive: true },
    { value: new RecordId('users', 'f'), inclusive: false }
);

const users = await db.query(`
    SELECT * FROM users 
    WHERE id IN $range
`, {
    range: idRange
}).collect();

Exclusive Ranges

// Exclusive range (not including boundaries)
const exclusive = new Range(
    { value: 0, inclusive: false },
    { value: 100, inclusive: false }
);
// Matches: 0 < x < 100

const results = await db.query(`
    SELECT * FROM measurements 
    WHERE value IN $range
`, {
    range: exclusive
}).collect();

Half-Open Ranges

// Half-open range [start, end)
const halfOpen = new Range(
    { value: 0, inclusive: true },
    { value: 10, inclusive: false }
);
// Matches: 0 <= x < 10

// Common for array-like indexing
const items = await db.query(`
    SELECT * FROM items 
    WHERE index IN $range
`, {
    range: halfOpen
}).collect();

Multiple Ranges

// Define multiple severity levels
const low = new Range(
    { value: 0, inclusive: true },
    { value: 3, inclusive: true }
);

const medium = new Range(
    { value: 4, inclusive: true },
    { value: 6, inclusive: true }
);

const high = new Range(
    { value: 7, inclusive: true },
    { value: 10, inclusive: true }
);

// Query by severity
const criticalIssues = await db.query(`
    SELECT * FROM issues 
    WHERE severity IN $range
`, {
    range: high
}).collect();

Range Queries in Application

function queryByRange<T>(
    start: T,
    end: T,
    inclusive: boolean = true
): Range<T, T> {
    return new Range(
        { value: start, inclusive },
        { value: end, inclusive }
    );
}

// Usage
const dateRange = queryByRange(
    DateTime.parse('2024-01-01'),
    DateTime.parse('2024-12-31')
);

const orders = await db.query(`
    SELECT * FROM orders 
    WHERE created_at IN $range
`, {
    range: dateRange
}).collect();

Range Notation

SurrealDB uses specific notation for ranges:

Best Practices

1. Use Appropriate Inclusivity

// Good: Inclusive for dates (including full days)
const dateRange = new Range(
    { value: DateTime.parse('2024-01-01T00:00:00Z'), inclusive: true },
    { value: DateTime.parse('2024-01-31T23:59:59Z'), inclusive: true }
);

// Good: Exclusive end for array-like indexing
const arrayRange = new Range(
    { value: 0, inclusive: true },
    { value: 10, inclusive: false }
); // [0, 10)

2. Type Safety

// Good: Explicit types
const range: Range<number, number> = new Range(
    { value: 1, inclusive: true },
    { value: 100, inclusive: true }
);

// Good: Consistent types
const dateRange: Range<DateTime, DateTime> = new Range(
    { value: DateTime.now(), inclusive: true },
    { value: DateTime.now().plus(Duration.parse('1d')), inclusive: true }
);

3. Validate Bounds

// Good: Ensure start <= end
function createRange<T>(start: T, end: T): Range<T, T> | null {
    if (start > end) {
        console.error('Invalid range: start must be <= end');
        return null;
    }
    
    return new Range(
        { value: start, inclusive: true },
        { value: end, inclusive: true }
    );
}

Use Cases

• Filtering - Filter records by numeric, date, or other ordered values
• Pagination - Query records in ID ranges
• Time Windows - Define time-based query windows
• Price Filtering - E-commerce price range searches
• Score Categorization - Categorize by score ranges (grades, ratings)
• Geographic Bounds - Coordinate ranges for maps

See Also

• RecordIdRange - Range of record IDs
• DateTime - Datetime values for date ranges
• Decimal - Precise numbers for price ranges
• Data Types Overview - All custom data types
• SurrealQL Ranges - Database range syntax