Math Functions

Qubit maps standard Java math methods to JPA CriteriaBuilder functions at build time. Write natural Java expressions using Math.* methods, and Qubit generates the equivalent JPA criteria calls.

Unary Functions

Use Math.abs(), Math.sqrt(), Math.ceil(), Math.floor(), Math.exp(), and Math.log() directly in lambdas:

// Absolute value: find people within 5 years of age 30
List<Person> nearby = personRepository
    .where((Person p) -> Math.abs(p.age - 30) < 5)
    .toList();

// Square root
List<Person> highEarners = personRepository
    .where((Person p) -> Math.sqrt(p.salary) > 300)
    .toList();

// Ceiling and floor
List<Person> results = personRepository
    .where((Person p) -> Math.ceil(p.rating) >= 4)
    .toList();

// Natural logarithm (Math.log maps to JPA LN)
List<Person> filtered = personRepository
    .where((Person p) -> Math.log(p.salary) > 10)
    .toList();

Sign and Negation

Use Integer.signum() or Long.signum() for the sign of a number, and the unary - operator for negation:

// Sign: returns -1, 0, or 1
List<Person> positiveBalance = personRepository
    .where((Person p) -> Integer.signum(p.balance) > 0)
    .toList();

// Unary negation
List<Person> results = personRepository
    .where((Person p) -> -p.age < -18)
    .toList();

Binary Functions

Math.pow() takes two arguments — the base and the exponent:

// Power: x^y
List<Person> results = personRepository
    .where((Person p) -> Math.pow(p.score, 2) > 10000)
    .toList();

// With captured variable
double exponent = 3.0;
List<Person> results = personRepository
    .where((Person p) -> Math.pow(p.rating, exponent) > 100)
    .toList();

Rounding

Qubit supports two forms of rounding:

Math.round() rounds to the nearest integer:

List<Person> results = personRepository
    .where((Person p) -> Math.round(p.salary) > 50000)
    .toList();

QubitMath.round() rounds to an arbitrary number of decimal places. Import the marker class and specify the precision:

import io.quarkiverse.qubit.QubitMath;

// Round to 2 decimal places
List<Person> results = personRepository
    .where((Person p) -> QubitMath.round(p.salary, 2) > 50000)
    .toList();

In Projections

Math functions work in select() projections:

List<Double> rootSalaries = personRepository
    .select((Person p) -> Math.sqrt(p.salary))
    .toList();

List<PersonDTO> dtos = personRepository
    .select((Person p) -> new PersonDTO(
        p.firstName,
        Math.abs(p.age - 30)))
    .toList();

Reference

All supported math functions and their JPA mappings:

Java Expression JPA CriteriaBuilder JPA Version

Math.abs(x)

cb.abs(expr)

2.0

-x (unary negation)

cb.neg(expr)

2.0

Math.sqrt(x)

cb.sqrt(expr)

2.0

Integer.signum(x) / Long.signum(x)

cb.sign(expr)

3.1

Math.ceil(x)

cb.ceiling(expr)

3.1

Math.floor(x)

cb.floor(expr)

3.1

Math.exp(x)

cb.exp(expr)

3.1

Math.log(x)

cb.ln(expr)

3.1

Math.pow(x, y)

cb.power(expr, expr)

3.1

Math.round(x)

cb.round(expr, 0)

3.1

QubitMath.round(x, n)

cb.round(expr, n)

3.1
All functions listed above are standard JPA CriteriaBuilder methods. No database-specific cb.function() calls are used. Trigonometric functions (sin, cos, tan) are Hibernate-only extensions and are not supported.