I can update my One2many field with the following function called from a button:

@api.multi
def getlinks(self):
    self.salary.unlink()
    staffs = self.env['sankeremployee.monthly'].search([('employee', '=', self.employee.id)])
    data = []
    for staff in staffs:
         data.append((0, 0, {'employee': staff.employee.id, 'basic': staff.basic}))
    self.salary = data

However, I would like to do this using an onchange function. When I tried this with the following code, the record is created but the field values are not passed on. Is there some way of correcting this? I am using version 12.

@api.onchange('employee')
def getlinks(self):
    self.salary.unlink()
    staffs = self.env['sankeremployee.monthly'].search([('employee', '=', self.employee.id)])
    data = []
    for staff in staffs:
        data.append((0, 0, {'employee': staff.employee.id, 'basic': staff.basic}))
    self.salary = data