2
我试图开始南数据迁移。我发现这个问题:South data migration 'instance' error when using south freeze orm,并尝试列出的命令,但它似乎没有帮助。Django,South和--freeze命令
我有两个应用程序A和B在我的项目,这里有他们的模型:
# /app_A/models.py
from django.db import models
class Employee(models.Model):
name = models.CharField(max_length = 100)
department = models.ForeignKey("Department")
manager = models.ForeignKey("self", blank = True, null = True)
birthdate = models.DateField()
# /app_B/models.py
from django.db import models
from hr_manager.models import Employee
class Task(models.Model):
title = models.CharField(max_length=50)
description = models.TextField()
assigned_to = models.ForeignKey(Employee, null=False, blank=False)
seniority = models.IntegerField(default=0)
age = models.IntegerField(default=0)
我试图生成APP_B数据迁移,使其计算员工工作的年龄和senority被分配并存储在任务本身中。我跑了:
./manage.py datamigration app_B populate_age_and_senority --freeze app_A
--freeze选项应该使app_A的模型在通过orm ['app_1。']进行迁移时可用。然后我编辑创建这样的迁移:
from south.db import db
from south.v2 import DataMigration
from django.db import models
class Migration(DataMigration):
def forwards(self, orm):
import datetime
def calculate_age(born):
''' Returns the age from a starting date '''
...
birthdate = orm['hr_manager.Employee'].birthdate
date_joined = orm['hr_manager.EmployeeHistory'].date_joined
orm.Task.age = calculate_age(birthdate)
orm.Task.seniority = calculate_age(date_joined)
orm.Task.save()
def backwards(self, orm):
raise RuntimeError("Cannot reverse this migration.")
然后跑去:
./manage.py migrate app_B
这是我获得的:
AttributeError: type object 'Employee' has no attribute 'birthdate'
难道我做错了什么?
在此先感谢您的帮助!
确实,这工作得很好。 谢谢@dlamotte。 :) – 2011-06-03 15:13:42