Question

我正在使用peewee访问远程 MySql 数据库以检索需要在 Django 应用程序中显示的数据。这意味着peewee并不是真正用于访问主数据库，而只是喜欢定义自定义模型：

databases.py中的示例：

from django.conf import settings
from playhouse.pool import PooledMySQLDatabase

database = PooledMySQLDatabase(
    settings.DB_PEEWEE,
    **{
        "use_unicode": True,
        "charset": "utf8",
        "max_connections": 32,
        "stale_timeout": 300,  # 5 minutes.
        "password": settings.DB_PEEWEE_PSWRD,
        "user": settings.DB_PEEWEE_USER,
        "host": settings.DB_PEEWEE_HOST,
        "port": settings.DB_PEEWEE_PORT,
    }
)

在models.py中：

from .databases import database


class BaseModel(peewee.Model):
    class Meta:
        database = database 


class CountryGroups(BaseModel):
    africa = peewee.CharField(null=True)
    group_code = peewee.AutoField()
    group_name = peewee.CharField()
    latin_eur = peewee.CharField(null=True)
    type = peewee.CharField()

    class Meta:
        table_name = "country_groups"
...
# other main django models

因此可以轻松地从views.py文件中以如下方式调用模型：

CountryGroups_list = (
        CountryGroups.select()
        .where(CountryGroups.group_name << ["ERROR", "INFO"])
        .order_by(CountryGroups.group_name.desc())
        .limit(1000)
    )

我可以很好地运行查询。但是在连接断开的24小时后，我得到一个错误：

(2006, "MySQL server has gone away (error(32, 'Broken pipe'))")

在Django中解决此问题的建议方法是使用middleware，但这是假设在这种情况下，与peewee相关的数据库是主要数据库，并导致了错误像这样一个：

File "/home/user/Dev/project/project/wsgi.py", line 14, in <module>
    from configurations.wsgi import get_wsgi_application
  File "/home/user/.virtualenvs/project/lib/python3.5/site-packages/configurations/wsgi.py", line 14, in <module>
    application = get_wsgi_application()
  File "/home/user/.virtualenvs/project/lib/python3.5/site-packages/django/core/wsgi.py", line 13, in get_wsgi_application
    return WSGIHandler()
  File "/home/user/.virtualenvs/project/lib/python3.5/site-packages/django/core/handlers/wsgi.py", line 135, in __init__
    self.load_middleware()
  File "/home/user/.virtualenvs/project/lib/python3.5/site-packages/django/core/handlers/base.py", line 37, in load_middleware
    mw_instance = middleware(handler)
TypeError: object() takes no parameters

所以我的问题是，如何对通用的数据库模型实现自动的 connect（）和 close（）没有得到错误？

Answer 1

您需要编写一个新的Django风格的中间件。我已经相应地更新了文档：

http://docs.peewee-orm.com/en/latest/peewee/database.html#django

def PeeweeConnectionMiddleware(get_response):
    def middleware(request):
        database.connect()
        try:
            response = get_response(request)
        finally:
            if not database.is_closed():
                database.close()
        return response
    return middleware

Mysql不再使用peewee作为Django中的第二个数据库

1 个答案: