我使用 Django 1.8

我有model.py，像这样

class Product(models.Model):

    name = models.CharField(max_length=150)
    created_at = models.DateField(auto_now_add = True)
    modified_at = models.DateField(auto_now = True)

MySQL 有一个表 'created_at' 和 'modified_at' 有这样的数据 "2015-11-02" 我想将数据更改为“2015-11-02 14:54:22”

我把 models.py 改成了这个

class Product(models.Model):

    name = models.CharField(max_length=150)
    created_at = models.DateTimeField(auto_now_add = True)
    modified_at = models.DateTimeField(auto_now = True)

然后我在控制台中运行迁移

python manage.py makemigrations
python manage.py migrate

但是什么也没发生。 MySQL 表中的数据没有变化，当我添加新信息时，在 MySQL 中以旧模式“2015-11-02”添加时间

我如何改变它们？

附上 Lego Stormtroopr

谢谢，我阅读了 Django 教程，并编写了这段代码

from __future__ import unicode_literals
from django.db import migrations, models
import datetime

def add_time_to_date(apps, schema_editor):
    datetables = apps.get_model("product", "Product")
    delta = datetime.timedelta(hours=1)
    for x in datetables.objects.all():
        x.created_at = x.created_at + delta
        x.modified_at = x.modified_at + delta
        x.save()


class Migration(migrations.Migration):
    dependencies = [
        ('product', '0003_auto_20151110_1726'),
    ]

    operations = [
        migrations.RunPython(add_time_to_date),
     ]

在那之后，我跑

   python manage.py migrate

控制台写了这个:

    Operations to perform:
      Synchronize unmigrated apps: staticfiles, messages
      Apply all migrations: admin, contenttypes, product, auth, sessions
    Synchronizing apps without migrations:
      Creating tables...
        Running deferred SQL...
      Installing custom SQL...
    Running migrations:
      Rendering model states... DONE
      Applying product.0004_auto_20151110_1821.../home/djangojunior2/virtualpython2/lib/python2.7/site-packages/django/db/models/fields/__init__.py:1414: RuntimeWarning: DateTimeField Product.created_at         received a naive datetime (2015-11-02 00:00:00) while time zone support is active.
      RuntimeWarning)

    /home/djangojunior2/virtualpython2/lib/python2.7/site-packages/django/db/backends/mysql/base.py:124: Warning: Data truncated for column 'modified_at' at row 1
      return self.cursor.execute(query, args)

    /home/djangojunior2/virtualpython2/lib/python2.7/site-packages/django/db/models/fields/__init__.py:1414: RuntimeWarning: DateTimeField Product.created_at received a naive datetime (2015-11-08 00:00:00) while time zone support is active.
      RuntimeWarning)

    /home/djangojunior2/virtualpython2/lib/python2.7/site-packages/django/db/models/fields/__init__.py:1414: RuntimeWarning: DateTimeField Product.created_at received a naive datetime (2015-11-09 00:00:00) while time zone support is active.
      RuntimeWarning)

    /home/djangojunior2/virtualpython2/lib/python2.7/site-packages/django/db/models/fields/__init__.py:1414: RuntimeWarning: DateTimeField Product.created_at received a naive datetime (10 00:00:00) while time zone support is active.
      RuntimeWarning)

     OK

我检查了 Mysql 数据库(使用 mysql-console)，但没有任何反应。日期仍然是“2015-11-02” 如果我添加新数据，在表 modified_at 和 created_at 中，日期添加到旧样式(“2015-11-02”)。

我做错了什么？

最佳答案

migrate 命令只处理schema 迁移，不处理数据迁移。部分问题在于许多数据库后端将日期和日期时间存储在相同的字段类型中，而 Django 将它们强制转换为正确的类型。

所以要做到这一点，你需要做一个 data migration

迁移的代码看起来像这样，但这取决于添加到无时间日期的时间:

from django.db import models, migrations

def date_to_datetime(apps, schema_editor):
    # We can't import the Person model directly as it may be a newer
    # version than this migration expects. We use the historical version.
    Product = apps.get_model("yourappname", "Product")
    for product in Product.objects.all():
        # convert a date to a date time on the product instance
        product.save()

class Migration(migrations.Migration):

    dependencies = [
        ('yourappname', 'migration_name'),
    ]

    operations = [
        migrations.RunPython(date_to_datetime),
    ]

关于python - Django 1.8 将日期字段更改为 DateTimeField，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33621344/