Question

我使用Django 1.8

我有model.py，就像这样

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＆＃39; created_at＆＃39;和＆＃39; modified_at＆＃39;谁拥有这样的数据＆＃34; 2015-11-02＆＃34; 我想将数据更改为＆＃34; 2015-11-02 14：54：22＆＃34;

我将models.py更改为此

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

但什么都没发生。 MySQL表中的数据不会改变，当我添加新信息时，在MySQL中添加旧模式的时间＆＃34; 2015-11-02＆＃34;

我如何改变它们？

PS Lego Stormtroopr

Thanx，我读了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),
     ]

之后，我跑

   python manage.py migrate

Console写道：

    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 db（使用了mysql-console），没有任何反应。日期仍然是＆＃34; 2015-11-02＆＃34;如果我添加新数据，在表modified_at和created_at中，日期添加到旧样式（＆＃34; 2015-11-02＆＃34;）。

我做错了什么？

Answer 1

package mvc; import java.awt.Container; import javax.swing.JButton; import javax.swing.JLabel; import javax.swing.JPanel; public class Panel extends JPanel { private JButton b1; private JLabel l1; public Panel(){ Container pane = new JPanel(); b1 = new JButton("Button"); pane.add(b1); l1 = new JLabel("Label for the button"); pane.add(l1); } }命令仅处理架构迁移，而不处理数据迁移。部分问题是许多数据库后端在同一字段类型中存储日期和日期时间，而Django则将它们强制为正确的类型。

要做到这一点，你还需要做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：

migrate

Django 1.8将datefield更改为DateTimeField

1 个答案: