The SQL service provided by Hazelcast allows you to query data stored in IMap declaratively.
| The SQL feature is currently in beta. The compatibility between versions is not guaranteed. API might change between versions without notice. | 
Example: How to Query an IMap using SQL
Consider that we have a map called emp that contains values of type Employee:
public class Employee implements Serializable {
    private String name;
    private int age;
    public Employee(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public int getAge() {
        return age;
    }
}
The following code prints names of the employees whose age is less than 30:
try (SqlResult result = hazelcastInstance.getSql().execute("SELECT name FROM emp WHERE age < ?", 30)) {
    for (SqlRow row : result) {
        String name = row.getObject(0);
        System.out.println(name);
    }
}
You can run the same code snippet from a member or a client.