标签:test syn route The write 分布式 min name return
最近在研究微服务和分布式,设计到了数据库分库,记录一下
首先,创建多个数据库,如果是已经生成的数据库,可以分库,这里我是新创建的项目,刚好可以用来尝试
我是用docker创建的mysql数据库容器
拉取docker镜像:
docker pull mysql:5.7
创建容器:
docker run --name=mysql5.7 -p 13306:3306 -e MYSQL_ROOT_PASSWORD=123456 -d mysql:5.7
创建多个mysql容器之后,django配置好相应数据库,我这里分成了三个数据库,一个是默认,放django的user,group,permission,session之类的,另外一个是order和sale两个app的,这里我打算下一步微服务的时候再拆开,这里先记录分库的事情,数据库代码如下:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'HOST': '192.168.1.112',
'PORT': '13308',
'NAME': 'default',
'USER': 'root',
'PASSWORD': '0123456789',
'TEST': {
'MIRROR': 'default'
}
},
'sale': {
'ENGINE': 'django.db.backends.mysql',
'HOST': '192.168.1.112',
'PORT': '13306',
'NAME': 'sale',
'USER': 'root',
'PASSWORD': '0123456789',
'TEST': {
'MIRROR': 'default'
}
},
'order': {
'ENGINE': 'django.db.backends.mysql',
'HOST': '192.168.1.112',
'PORT': '13307',
'NAME': 'order',
'USER': 'root',
'PASSWORD': '0123456789',
'TEST': {
'MIRROR': 'default'
}
}
}
分库之后,在settings.py同级目录下,创建一个databaserouter
DATABASE_MAPPING = {
# example:
# 'app_name':'database_name',
'sale': 'sale',
'order': 'order',
'admin': 'default',
'auth': 'default',
'contenttypes': 'default',
'sessions': 'default',
}
class DBAppsRouter(object):
def db_for_read(self, model, **hints):
""""Point all read operations to the specific database."""
if model._meta.app_label in DATABASE_MAPPING:
return DATABASE_MAPPING[model._meta.app_label]
return None
def db_for_write(self, model, **hints):
"""Point all write operations to the specific database."""
if model._meta.app_label in DATABASE_MAPPING:
return DATABASE_MAPPING[model._meta.app_label]
return None
def allow_relation(self, obj1, obj2, **hints):
"""Allow any relation between apps that use the same database."""
db_obj1 = DATABASE_MAPPING.get(obj1._meta.app_label)
db_obj2 = DATABASE_MAPPING.get(obj2._meta.app_label)
if db_obj1 and db_obj2:
if db_obj1 == db_obj2:
return True
else:
return False
return None
def allow_syncdb(self, db, model):
"""Make sure that apps only appear in the related database."""
if db in DATABASE_MAPPING.values():
return DATABASE_MAPPING.get(model._meta.app_label) == db
elif model._meta.app_label in DATABASE_MAPPING:
return False
return None
def allow_migrate(self, db, app_label, model=None, **hints):
"""
Make sure the auth app only appears in the 'auth_db'
database.
"""
if db in DATABASE_MAPPING.values():
return DATABASE_MAPPING.get(app_label) == db
elif app_label in DATABASE_MAPPING:
return False
return None
这里一定要把DATABASE_MAPPING里面的app名字和app名字对应,不然会读写不到,具体可以看上述代码,然后在模型类后面给每个模型添加一个app_label:
class Meta:
app_label = 'order'
最后就是migrate数据库了,先makemigrations order
,然后migrate --database order
后面sale app一样
标签:test syn route The write 分布式 min name return
原文地址:https://www.cnblogs.com/yuruhao/p/12490034.html