Django之MySQL配置部署
mysql5.0以上版本支援三種sql_mode:ANSI、TRADITIONAL和STRICT_TRANS_TABLES。
-
ANSI模式:寬鬆模式,對插入資料進行校驗,如果不符合定義型別或長度,對資料型別調整或截斷儲存,報warning警告。
-
TRADITIONAL模式:嚴格模式,當向mysql資料庫插入資料時,進行資料的嚴格校驗,保證錯誤資料不能插入,報error錯誤。用於事物時,會進行事物的回滾。
-
STRICT_TRANS_TABLES模式:嚴格模式,進行資料的嚴格校驗,錯誤資料不能插入,報error錯誤。
1、連線操作單資料庫
- django預設使用的是sqlite3資料庫,settings.py
# 修改前
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
}
- 修改後
DATABASES = { 'books': { 'ENGINE': 'django.db.backends.mysql', 'HOST':'172.20.25.1', 'PORT':'3306', 'USER':'bmanager', 'PASSWORD':'MyNewPass0!', 'NAME': 'books', # 庫名, 要連線的資料庫,連線前需要建立好 'OPTIONS': { 'init_command': "SET sql_mode='STRICT_TRANS_TABLES'", }, } }
注意1:
NAME即資料庫的名字,在mysql連線前該資料庫必須已經建立,而上面的sqlite資料庫下的db.sqlite3則是專案自動建立 USER和PASSWORD分別是資料庫的使用者名稱和密碼。設定完後,再啟動我們的Django專案前,我們需要啟用我們的mysql。然後,啟動專案,會報錯:no module named MySQLdb 。這是因為django預設你匯入的驅動是MySQLdb,可是MySQLdb 對於py3有很大問題,所以我們需要的驅動是PyMySQL 所以,我們只需要找到app專案名檔案下的__init__.py,在裡面寫入:
import pymysql pymysql.install_as_MySQLdb()
- 設定表結構,models.py
class Books_info(models.Model):
id = models.AutoField(primary_key=True)
createtime = models.DateTimeField('建立時間', auto_now = True)
name = models.CharField(max_length=32)
price = models.IntegerField()
author = models.CharField(max_length=32)
publishing_house = models.CharField(max_length=32)
publication_time = models.IntegerField()
num = models.IntegerField()
最後通過兩條資料庫遷移命令即可在指定的資料庫中建立表
- 生成資料庫對應關係,生成指定appname的models.py裡邊的對映
python3 manage.py makemigrations appname
- 依據對映關係生成對應的表
python3 manage.py migrate appname
注意2:
確保配置檔案中的INSTALLED_APPS中寫入我們建立的app名稱
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
"book"
]
注意3:
如果報錯如下:
django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.3 or newer is required; you have 0.7.11.None
MySQLclient目前只支援到python3.4,因此如果使用的更高版本的python,需要修改如下:
通過查詢路徑C:\Programs\Python\Python36-32\Lib\site-packages\Django-2.0-py3.6.egg\django\db\backends\mysql
這個路徑裡的檔案把
if version < (1, 3, 3):
raise ImproperlyConfigured("mysqlclient 1.3.3 or newer is required; you have %s" % Database.__version__)
註釋掉 就OK了。
注意4:
如果想列印orm轉換過程中的sql,需要在settings中進行如下配置:
LOGGING = {
'version': 1,
'disable_existing_loggers': False,
'handlers': {
'console':{
'level':'DEBUG',
'class':'logging.StreamHandler',
},
},
'loggers': {
'django.db.backends': {
'handlers': ['console'],
'propagate': True,
'level':'DEBUG',
},
}
}
2、連線操作多資料庫
- 新增新庫,修改settings.py
DATABASES = {
'books': {
'ENGINE': 'django.db.backends.mysql',
'HOST':'172.20.25.1',
'PORT':'3306',
'USER':'bmanager',
'PASSWORD':'MyNewPass0!',
'NAME': 'books', # 庫名
'OPTIONS': {
'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
},
'users': {
'ENGINE': 'django.db.backends.mysql',
'HOST':'172.20.25.2',
'PORT':'3306',
'USER':'umanager',
'PASSWORD':'MyNewPass1!',
'NAME': 'users', # 庫名
'OPTIONS': {
'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
},
}
}
- 新增資料庫的路由,修改settings.py
DATABASE_ROUTERS = ['mysite.database_router.DatabaseAppsRouter'] # mysite專案目錄名
## app指定資料庫
DATABASE_APPS_MAPPING = {
# example:
# 'app_name':'database_name',
'booksModel':'books',
'usersModel':'users',
}
- 在settings.py同級目錄下新建路由檔案,database_router.py
from django.conf import settings
DATABASE_MAPPING = settings.DATABASE_APPS_MAPPING
class DatabaseAppsRouter(object):
"""
A router to control all database operations on models for different
databases.
In case an app is not set in settings.DATABASE_APPS_MAPPING, the router
will fallback to the `default` database.
Settings example:
DATABASE_APPS_MAPPING = {'app1': 'db1', 'app2': 'db2'}
"""
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
- 情況一:遠端資料庫中表結構及資料已存在
# 拉取表結構
python3 manage.py inspectdb --database=users >> usersModel/models.py
python3 manage.py migrate usersModel --fake
- 情況二:遠端資料庫表結構及資料不存在,則需要修改配置
-
- 修改 usersModel/models.py 檔案
class Users_info(models.Model):
id = models.AutoField(primary_key=True)
createtime = models.DateTimeField('建立時間', auto_now = True)
name = models.CharField(max_length=32)
age = models.IntegerField()
sex = models.CharField(max_length=10)
identification_numbers = models.IntegerField()
identity = models.CharField(max_length=32)
phone_number = models.IntegerField()
job = models.CharField(max_length=32)
address = models.CharField(max_length=128)
-
- 刪除該app名字下的migrations檔案
rm -fr migrations/*
rm __pycache__/*
-
- 進入資料庫,找到django_migrations的表,刪除該app名字的所有記錄。
truncate table django_migrations where app='appname';
-
- 建立新表
python3 manage.py makemigrations
python3 manage.py migrate
-
- 指定資料庫
class Users_info(models.Model):
id = models.AutoField(primary_key=True)
createtime = models.DateTimeField('建立時間', auto_now = True)
name = models.CharField(max_length=32)
age = models.IntegerField()
sex = models.CharField(max_length=10)
identification_numbers = models.IntegerField()
identity = models.CharField(max_length=32)
phone_number = models.IntegerField()
job = models.CharField(max_length=32)
address = models.CharField(max_length=128)
class Meta:
app_label = 'users'
http://doc.codingdict.com/django/topics/migrations.html