Database Reference
In-Depth Information
Query HBase using Kundera
In order to query HBase using Kundera, you irst need to create a
Query
instance
using
EntityManager
and then call the
getResultList()
method of the
query
class
to get a list of results. The following code shows a few examples of querying HBase
using Kundera:
//Select without where cause 1.e. Select all.
String queryString = "Select e from Employee e";
Query query = em.createQuery(queryString);
List<Employee> employees = query.getResultList();
System.out.println(employees.size());
employee = employees.get(0);
System.out.println(employee.getEmployeeId());
System.out.println(employee.getEmployeeName());
System.out.println(employee.getAddress());
System.out.println(employee.getDepartment());
// Select Query with constraints on employee name.
queryString = "Select e from Employee e where e.employeeName=John";
query = em.createQuery(queryString);
employees = query.getResultList();
System.out.println(employees.size());
employee = employees.get(0);
System.out.println(employee.getEmployeeId());
System.out.println(employee.getEmployeeName());
System.out.println(employee.getAddress());
System.out.println(employee.getDepartment());
// Select specific columns only.
queryString = "Select e.employeeName, e.address from Employee e";
query = em.createQuery(queryString);
employees = query.getResultList();
System.out.println(employees.size());
employee = employees.get(0);
