django south 使用教程(1) django south 使用教程(2)

class Knight(models.Model):
    name = models.CharField(max_length=100)
    of_the_round_table = models.BooleanField()

E:\project\demo>manage.py schemamigration southtut --initial
Creating migrations directory at 'E:\project\demo\southtut\migrations'...#创建迁移目录migrations
Creating __init__.py in 'E:\project\demo\southtut\migrations'...#创建__init__.py
 + Added model southtut.Knight                                  #增加model
Created 0001_initial.py. You can now apply this migration with: ./manage.py migrate southtut#创建版本控制

E:\project\demo>manage.py migrate southtut --fake  #启动
Running migrations for southtut:                   #启动该app下的migrations
 - Migrating forwards to 0001_initial.             #正向前迁移
 > southtut:0001_initial
   (faked)

class Knight(models.Model):
    name = models.CharField(max_length=100)
    of_the_round_table = models.BooleanField()
    dances_whenever_able = models.BooleanField()  #新增

E:\project\demo>manage.py schemamigration southtut --auto  #此时用 --auto
 + Added field dances_whenever_able on southtut.Knight     #做出的改变
Created 0002_auto__add_field_knight_dances_whenever_able.py. #创建迁移版本

You can now apply this migration with: ./manage.py migrate southtut

E:\project\demo>manage.py migrate southtut
Running migrations for southtut:
 - Migrating forwards to 0002_auto__add_field_knight_dances_whenever_able.
 > southtut:0002_auto__add_field_knight_dances_whenever_able
 - Loading initial data for southtut.
No fixtures found.

#已存在的model且里面存有数据
class Contact(models.Model):
    name = models.CharField(max_length=30)
    email = models.EmailField()
    comment = models.CharField(max_length=100)
    def __unicode__(self):
        return self.name
    class Meta:
        db_table='contact'

#Contact
...
age = models.IntegerField()  #添加

manage.py schemamigration other --auto
.....#省略

manage.py migrate other
#...省略

#Contact
...
website = models.CharField(max_length=100,null=False)  #新增
..

E:\project\demo>manage.py schemamigration other --auto
 ? The field 'Contact.website' does not have a default specified, yet is NOT NULL.   #问题
 ? Since you are adding this field, you MUST specify a default value to use for existing rows. Would you like to:
 ?  1. Quit now, and add a default to the field in models.py    #退出，在models手动添加默认值
 ?  2. Specify a one-off value to use for existing columns now  #指定默认值
 ? Please select a choice:

.....
 ? Please select a choice: 2             #我的选择
 ? Please enter Python code for your one-off default value.
 ? The datetime module is available, so you can do e.g. datetime.date.today()
 >>> 'http://www.google.com'             #指定的默认值
 + Added field website on other.Contact  #添加成功
Created 0006_auto__add_field_contact_website.py. You can now apply this migration with: ./manage.py migrate other

#应用
E:\project\demo>manage.py migrate other
Running migrations for other:
 - Migrating forwards to 0006_auto__add_field_contact_website.
 > other:0006_auto__add_field_contact_website
 - Loading initial data for other.No fixtures found.

class Contact(models.Model):
    name = models.CharField(max_length=30,unique=True)#更改了
    email = models.EmailField()
    comment = models.CharField(max_length=100)
    website = models.CharField(max_length=100,null=False)  #新增
    def __unicode__(self):
        return self.name
    class Meta:
        db_table='contact'

E:\project\demo>manage.py schemamigration other --auto
 + Added unique constraint for ['name'] on other.Contact
Created 0007_auto__add_unique_contact_name.py. You can now apply this migration
with: ./manage.py migrate other

#还可以这样：
E:\project\demo>manage.py schemamigration --auto other