标签：python mysql django datefield
我使用Django 1.8
我有这样的model.py
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’谁有这样的数据“2015-11-02”
我想将数据更改为“2015-11-02 14:54:22”
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“2015-11-02”
我怎么改变它们？
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),
]
在那之后,我跑了
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“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”).
我究竟做错了什么？
解决方法:
migrate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,并且Django将它们强制转换为正确的类型.
所以要做到这一点你也需要做data migration.
迁移的代码看起来像这样,但它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),
]
标签：python,mysql,django,datefield 来源： https://codeday.me/bug/20190702/1357153.html
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