通过Accessor来取得相关的实体

来源：互联网发布：js添加class的css样式编辑：程序博客网时间：2024/06/07 19:39

概述
1. 通过主实体取得多个从实体
2. 通过从实体取得对应的主实体
3. 在Departments和Employees实体关系中通过员工取得对应的部门和通过部门取得部门下的所有员工
实现
1. 通过员工取得部门名称的代码如下：public String findEmpDepartment(long employeeId) { EmployeesImpl employee = retrieveEmployeeById(employeeId); if (employee != null) { DepartmentsImpl department = employee.getDepartments(); if (department != null) { return department.getDepartmentName(); } else { return "Unassigned"; } else { return null; } }}
2. 通过部门取得部门下的员工数代码如下：/* Access an associated Employees entity from the Department entity */public int findDeptEmployees(long departmentId) { DepartmentsImpl department = retrieveDepartmentById(departmentId); if (department != null) { RowIterator employees = department.getEmployees(); return (employees.getRowCount()); Row row ; while((row = employees.next())!= null){ EmployeesImpl emp = (EmployeesImpl)row; System.out.println(emp.getFirstName() + " " + emp.getLastName()); } } else { return 0; }}

本文转自Oracle Seeker：http://oracleseeker.com/2008/11/06/access_associated_entity_by_accessor_attribute/