Question

我有一个简单的核心数据问题。

I set up an employee entity and an employeeDetails entity. Both have a relationship pointing to the other to form a simple one-to-one relationship. Each employee has one employeeDetail.

我能够储存新雇员,必要时挑选新雇员。我的问题是,我如何同时储存配对员工,我如何找回手套中对应雇员的细节?

Thanks for any help you can provide.

Answer 1

在雇员的夫妻中,使用每个插入的触发器。

http://en.wikipedia.org/wiki/Database_trigger

Answer 2

我通过为各实体重新创建这一类别,解决了我的问题,核心数据将增加反映关系的动态变量。当我储存这些实体时,我创建了一名雇员和雇员。

- (void)addEmployee :(NSDictionary *)_employee {    

    // Create a new instance of the Employee entity.
    Employee *employee = (Employee *)[NSEntityDescription insertNewObjectForEntityForName:@"Employee" inManagedObjectContext:managedObjectContext];
    EmployeeDetails *employeeDetails = (EmployeeDetails *)[NSEntityDescription insertNewObjectForEntityForName:@"EmployeeDetails" inManagedObjectContext:managedObjectContext];

    // Add the new employee
    employee.firstName = [_employee objectForKey:@"first_name"];;
    employee.lastName = [_employee objectForKey:@"last_name"];;
/* --> */   employee.details = employeeDetails;  // Associate with details object

    // Add details
    employeeDetails.address    = [self getValue:[e objectForKey:@"street_address"]];   
    employeeDetails.cellPh     = [self getValue:[e objectForKey:@"cell"]];

    // Save the data
    NSError *error;
    if (![managedObjectContext save:&error]) {
        NSLog(@"core date save error: %@", error);
    }   
}

友情链接