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2020
09-24

Django多数据库配置及逆向生成model教程

在项目中我们每个app对应不同的数据库，其中有一个是从数据库逆向生成model，做个笔记。

1、修改项目的setting.py配置 ：

DATABASES = {
 'default': {
  'ENGINE': 'django.db.backends.mysql', # 默认用mysql
  'NAME': 'bk',      # 数据库名 (默认与APP_ID相同)
  'USER': 'root',      # 你的数据库user
  'PASSWORD': 'root',      # 你的数据库password
  'HOST': 'xxx.xxx.xxx.xxx',     # 开发的时候，使用localhost
  'PORT': '3306',      # 默认3306
 },
 'cloudsino_test': {
   'ENGINE': 'django.db.backends.mysql', # 默认用mysql
   'NAME': 'cloudsino_test',      # 数据库名 (默认与APP_ID相同)
   'USER': 'root',      # 你的数据库user
   'PASSWORD': 'root',      # 你的数据库password
   'HOST': 'xxx.xxx.xxx.xxx',     # 开发的时候，使用localhost
   'PORT': '3306',      # 默认3306
  },
}

# 设置数据库的路由规则方法
DATABASE_ROUTERS = ['conf.database_router.DatabaseAppsRouter']

# 设置APP对应的数据库路由表，哪个app要连接哪个数据库，没有指定会用default那个。
DATABASE_APPS_MAPPING = {
 # example:
 #'app_name':'database_name',
 'home_application': 'cloudsino_test',
 'cmdb': 'default',
}

2、新建database_router.py：

在与setting.py文件同级的目录下新建database_router.py文件：

# -*- coding: utf-8 -*-
from settings_development import DATABASE_APPS_MAPPING

DATABASE_MAPPING = DATABASE_APPS_MAPPING


class DatabaseAppsRouter(object):
 def db_for_read(self, model, **hints):
  """"建议model类型对象从哪一个数据库读取."""
  if model._meta.app_label in DATABASE_MAPPING:
   return DATABASE_MAPPING[model._meta.app_label]
  return None

 def db_for_write(self, model, **hints):
  """建议model类型对象的写入操作应该使用哪个数据库"""
  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.
  	如果obj1 和obj2 之间应该允许关联则返回True，如果应该防止关联则返回False，如果路由无法判断则返回None
  """
  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.
  定义迁移操作是否允许在别名为db的数据库上运行。如果操作应该运行则返回True ，如果不应该运行则返回False，如果路由无法判断则返回None。
  """
  if db in DATABASE_MAPPING.values():
   return DATABASE_MAPPING.get(app_label) == db
  elif app_label in DATABASE_MAPPING:
   return False
  return None

3.逆向生成model：

在terminal中输入以下命令，使用名为cloudsino_test的DATABASE来逆向生成model到home_application这个app的models.py：

python manage.py inspectdb --database=cloudsino_test > home_application/models.py

逆向生成的model：

# This is an auto-generated Django model module.
# You'll have to do the following manually to clean this up:
# * Rearrange models' order
# * Make sure each model has one field with primary_key=True
# * Remove `managed = False` lines if you wish to allow Django to create, modify, and delete the table
# Feel free to rename the models, but don't rename db_table values or field names.
#
# Also note: You'll have to insert the output of 'django-admin sqlcustom [app_label]'
# into your database.
from __future__ import unicode_literals

from django.db import models


class CloudsinoCpuinfo(models.Model):
 corenumber = models.CharField(max_length=128)
 frequency = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 name = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 device = models.ForeignKey('CloudsinoDevice', blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_cpuinfo'


class CloudsinoDevice(models.Model):
 sn = models.CharField(max_length=128)
 app = models.CharField(max_length=128)
 business_chargeby1 = models.CharField(max_length=128)
 business_chargeby2 = models.CharField(max_length=128)
 chargeby1 = models.CharField(max_length=128)
 chargeby2 = models.CharField(max_length=128)
 description = models.CharField(max_length=128)
 device_status = models.CharField(max_length=128)
 devicename = models.CharField(max_length=128)
 field1 = models.CharField(max_length=128)
 field2 = models.CharField(max_length=128)
 field3 = models.CharField(max_length=128)
 field4 = models.CharField(max_length=128)
 field5 = models.CharField(max_length=128)
 frame_posiniton = models.CharField(max_length=128)
 framename = models.CharField(max_length=128)
 ip = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 model = models.CharField(max_length=128)
 os = models.CharField(max_length=128)
 position_desc = models.CharField(max_length=128)
 roomarea = models.CharField(max_length=128)
 roomname = models.CharField(max_length=128)
 servicetag = models.CharField(max_length=128)
 shape = models.CharField(max_length=128)
 specification = models.CharField(max_length=128)
 subtype = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 ucount = models.CharField(max_length=128)

 class Meta:
  managed = False
  db_table = 'cloudsino_device'


class CloudsinoDevicetype(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 status = models.CharField(max_length=128)

 class Meta:
  managed = False
  db_table = 'cloudsino_devicetype'


class CloudsinoDiskinfo(models.Model):
 bus = models.CharField(max_length=128)
 formfactor = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 media = models.CharField(max_length=128)
 name = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 size = models.CharField(max_length=128)
 speed = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_diskinfo'


class CloudsinoFaninfo(models.Model):
 index = models.CharField(max_length=128)
 name = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_faninfo'


class CloudsinoHbacardinfo(models.Model):
 name = models.CharField(max_length=128)
 wwnn = models.CharField(max_length=128)
 wwpn = models.CharField(max_length=128)
 fc_switch = models.CharField(max_length=128)
 switch_port = models.CharField(max_length=128)
 switch_mac = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_hbacardinfo'


class CloudsinoManageinfo(models.Model):
 assetcode = models.CharField(max_length=128)
 department = models.CharField(max_length=128)
 express_code = models.CharField(max_length=128)
 service_level = models.CharField(max_length=128)
 shutdown_level = models.CharField(max_length=128)
 usage = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_manageinfo'


class CloudsinoManufacturertype(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 status = models.CharField(max_length=128)

 class Meta:
  managed = False
  db_table = 'cloudsino_manufacturertype'


class CloudsinoMemory(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 frequency = models.CharField(max_length=128)
 size = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 memoryinfo = models.ForeignKey('CloudsinoMemoryinfo', blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_memory'


class CloudsinoMemoryinfo(models.Model):
 max_dimmslots = models.CharField(max_length=128)
 mem_totalsize = models.CharField(max_length=128)
 memmax_capacitysize = models.CharField(max_length=128)
 populated_dimmslots = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_memoryinfo'


class CloudsinoNetworkinfo(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 mac = models.CharField(max_length=128)
 speed = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_networkinfo'


class CloudsinoOobnetwork(models.Model):
 ip = models.CharField(max_length=128)
 netmask = models.CharField(max_length=128)
 gateway = models.CharField(max_length=128)
 mac = models.CharField(max_length=128)
 ethernet_switch = models.CharField(max_length=128)
 swith_port = models.CharField(max_length=128)
 swith_mac = models.CharField(max_length=128)
 distribution_frame = models.CharField(max_length=128)
 distribution = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_oobnetwork'


class CloudsinoPciecard(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 loc = models.CharField(max_length=128)
 online_state = models.CharField(max_length=128)
 conntype = models.CharField(max_length=128)
 bandwidth = models.CharField(max_length=128)
 speed = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_pciecard'


class CloudsinoPowerinfo(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 model = models.CharField(max_length=128)
 outputpower = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_powerinfo'


class CloudsinoProductnetwork(models.Model):
 ip = models.CharField(max_length=128)
 netmask = models.CharField(max_length=128)
 gateway = models.CharField(max_length=128)
 mac = models.CharField(max_length=128)
 os = models.CharField(max_length=128)
 remote_type = models.CharField(max_length=128)
 remote_port = models.CharField(max_length=128)
 ethernet_switch = models.CharField(max_length=128)
 swith_port = models.CharField(max_length=128)
 swith_mac = models.CharField(max_length=128)
 distribution_frame = models.CharField(max_length=128)
 distribution = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_productnetwork'


class CloudsinoPurchasewarrantyinfo(models.Model):
 date_manuf = models.CharField(max_length=128)
 expiredate = models.CharField(max_length=128)
 price = models.CharField(max_length=128)
 purchase_order = models.CharField(max_length=128)
 purchase_order_name = models.CharField(max_length=128)
 purchase_supply = models.CharField(max_length=128)
 serviceagent = models.CharField(max_length=128)
 warrantyitem = models.CharField(db_column='warrantyItem', max_length=128) # Field name made lowercase.
 warrantyperiod = models.CharField(db_column='warrantyPeriod', max_length=128) # Field name made lowercase.
 warrantystartdate = models.CharField(db_column='warrantyStartDate', max_length=128) # Field name made lowercase.
 warrantytype = models.CharField(db_column='warrantyType', max_length=128) # Field name made lowercase.
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_purchasewarrantyinfo'


class CloudsinoRaidinfo(models.Model):
 name = models.CharField(max_length=128)
 type = models.CharField(max_length=128)
 cachesize = models.CharField(max_length=128)
 speed = models.CharField(max_length=128)
 manufacturer = models.CharField(max_length=128)
 partnumber = models.CharField(max_length=128)
 serialnumber = models.CharField(max_length=128)
 index = models.CharField(max_length=128)
 device = models.ForeignKey(CloudsinoDevice, blank=True, null=True)

 class Meta:
  managed = False
  db_table = 'cloudsino_raidinfo'


class DjangoMigrations(models.Model):
 app = models.CharField(max_length=255)
 name = models.CharField(max_length=255)
 applied = models.DateTimeField()

 class Meta:
  managed = False
  db_table = 'django_migrations'

补充知识：Django使用数据库生成模型类

正常的开发流程

在models.py中定义模型类，要求继承自models.Model

把应用加入settings.py文件的installed_app项

生成迁移文件

执行迁移生成表

使用模型类进行crud操作

使用数据库生成模型类

python manage.py inspectdb > app_name/models.py

例如：

python manage.py inspectdb > booktest/models.py

以上这篇Django多数据库配置及逆向生成model教程就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持自学编程网。

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