Examples with Predicate2 org.apache.calcite.linq4j.function.Predicate2 used on opensource projects

Example 1 with Predicate2

use of org.apache.calcite.linq4j.function.Predicate2 in project calcite by apache.

the class Linq4jTest method testAsQueryable.

@Test
public void testAsQueryable() {
    // "count" is an Enumerable method.
    final int n = Linq4j.asEnumerable(emps).asQueryable().count();
    assertEquals(4, n);
    // "where" is a Queryable method
    // first, use a lambda
    ParameterExpression parameter = Expressions.parameter(Employee.class);
    final Queryable<Employee> nh = Linq4j.asEnumerable(emps).asQueryable().where(Expressions.lambda(Predicate1.class, Expressions.equal(Expressions.field(parameter, Employee.class, "deptno"), Expressions.constant(10)), parameter));
    assertEquals(3, nh.count());
    // second, use an expression
    final Queryable<Employee> nh2 = Linq4j.asEnumerable(emps).asQueryable().where(Expressions.lambda(new Predicate1<Employee>() {

        public boolean apply(Employee v1) {
            return v1.deptno == 10;
        }
    }));
    assertEquals(3, nh2.count());
    // use lambda, this time call whereN
    ParameterExpression parameterE = Expressions.parameter(Employee.class);
    ParameterExpression parameterN = Expressions.parameter(Integer.TYPE);
    final Queryable<Employee> nh3 = Linq4j.asEnumerable(emps).asQueryable().whereN(Expressions.lambda(Predicate2.class, Expressions.andAlso(Expressions.equal(Expressions.field(parameterE, Employee.class, "deptno"), Expressions.constant(10)), Expressions.lessThan(parameterN, Expressions.constant(3))), parameterE, parameterN));
    assertEquals(2, nh3.count());
}