八、model_login2

shell模式

1、概述

一般操作数据库表的时候都是通过views.py文件进行操作的

在view.py文件中操作表单

操作表都是操作model.py里面的对象

2、基本数据访问

2.1、查询数据1

进入到shell模式

终端输入：

python3 manage.py shell

导入sign应用下面的molders.py中的Event、Guest两张表

终端输入：

from sign.models import Event,Guest

 利用table.objects.all()查询相对应数据库表的数据

终端输入：

>>> Event.objects.all()
<QuerySet [<Event: 糖猴子的发布会>, <Event: 糖糖>]>
>>> Guest.objects.all()
<QuerySet [<Guest: 张三>]>

 2.2、插入数据

因为发布会涉及到时间，需要引包datetime模块

定义一个变量e1--在数据库里面暂时看不到相对应的数据

保存e1变量保存到数据库里面

终端输入

>>> from datetime import datetime
>>> e1 = Event(id = 3,name = '新建的发布会',limit = '3000',status = False,address = '普陀',start_time = datetime(2017,8,10,14,0,0))
>>> e1.save()

 数据库页面展示

保存数据库信息的时候，警告信息如下（世界时相关）

>>> e1.save()
/usr/local/lib/python3.6/site-packages/django/db/models/fields/__init__.py:1451: RuntimeWarning: DateTimeField Event.start_time received a naive datetime (2017-08-10 14:00:00) while time zone support is active.
  RuntimeWarning)

 解决方案：需要退出shell模式之后，将setting.py文件中的 USE_TZ = False 修改成 USE_TZ = False即可

>>> quit()
 monkey@MacBook-Pro-7 � /usr/local/lib/python3.6/site-packages/guest � python3 manage.py shell
Python 3.6.3 (default, Oct 17 2017, 00:27:06)
[GCC 4.2.1 Compatible Apple LLVM 8.1.0 (clang-802.0.42)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>>
>>> from sign.models import Event,Guest
>>>
>>> from datetime import datetime
>>>
>>> e1 = Event(id = 6,name = '新建的发布会4',limit = '3000',status = False,address = '普陀4',start_time = datetime(2017,8,13,14,0,0))
>>> e1.save()
>>>

 数据库截图如下：

 

2.3、查询数据2

get方法

只支持精确查找

>>> e2 = Event.objects.get(name = "新建的发布会4")
>>> e2
<Event: 新建的发布会4>
>>> e2.address
'普陀4'

模糊搜索的保存

查询的数据不存在也会报错

>>> Event.objects.get(name = '发布会')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/usr/local/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/django/db/models/query.py", line 380, in get
    self.model._meta.object_name
sign.models.DoesNotExist: Event matching query does not exist.

filter方法

模糊搜索的时候直接输入的话会返回为空

Event.objects.filter(name = '发布会')
<QuerySet []>

不直接支持模糊查询，如果需要模糊搜索，需要在name后面加上__contains

Event.objects.filter(name__contains = '发布会')
<QuerySet [<Event: 糖猴子的发布会>, <Event: 新建的发布会>, <Event: 新建的发布会4>]>

 2.4、删除数据

利用delete的方法删除数据

>>> e3 = Event.objects.get(name = '新建的发布会')
>>> e3.delete()
(1, {'sign.Guest': 0, 'sign.Event': 1})
>>>
>>> Event.objects.all()
<QuerySet [<Event: 糖猴子的发布会>, <Event: 糖糖>, <Event: 新建的发布会4>]>
>>>

  2.5、更新数据

根据属性的唯一性，event_id来查询到相对应的数据

  g1.realname = 'lisi'  更新嘉宾表中的数据
  保存相对应更新的数据

>>> g1 = Guest.objects.get(event_id ='1')
>>>
>>> g1.realname = 'lisi'
>>> g1.save()
>>>
>>> Guest.objects.all()
<QuerySet [<Guest: lisi>]>

 3、mysql相关操作姿势

3.1、安装mysql

安装步骤可参照：http://www.jianshu.com/p/fd3aae701db9

安装完毕mysql

终端输入：mysql -u root -p（需要登陆密码，首次输入安装页面给出的密码）

mysql -u root -p

Enter password:
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 777
Server version: 5.7.20

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql>

3.2、查看当前数据库下面的所有库

进入到mysql环境，终端输入：show databases

如下代码，如果你一直用的都是安装时带的密码，所提示你重设代码

mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

 终端输入：mysql> set password = password('123456'); 设置密码

mysql> set password = password('123456');
Query OK, 0 rows affected, 1 warning (0.02 sec)

再次终端输入：show databases就会显示当前数据库下面的所有库

3.3、使用库并且展示库下面的所有表

mysql> use sys;    #选择使用数据库
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;   #显示数据库下面的所有表

 3.4、查看端口号

mysql> show global variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.01 sec)

 3.5、退出mysql，终端输入：ifconfig | grep "inet " | grep -v 127.0.0.1 （Mac不仅仅需要输入的是ifconfig）查看IP地址

monkey@MacBook-Pro-7 � ~ � ifconfig | grep "inet " | grep -v 127.0.0.1
	inet xx.xx.xx.xxx(ip地址) netmask 0xffffff00 broadcast 10.12.49.255

 3.6、本地登陆

进入到mysql命令

终端输入：MySQL -uroot -p123456   创建登陆账号

 monkey@MacBook-Pro-7 � ~ � mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 802
Server version: 5.7.20 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

创建远程登陆用户并授权

mysql> grant all PRIVILEGES on test_db.* to root@'XX.XX.XX.XXX'（IP地址）  identified by '123456';
Query OK, 0 rows affected, 1 warning (0.01 sec)

用mysql客户端 输入host（IP地址）、port、用户名、密码登陆即可

3.7、本地创建数据库表

4、修改Django数据库配置

4.1、setting文件下面添加mysql数据库连接信息

#配置mysql数据库链接

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'HOST': '127.0.0.1',  #IP地址
        'PORT': '3306',   #端口号
        'NAME': 'dev_guest',   #表名
        'USER': 'root',   #账户
        'PASSWORD': '123456',   #密码
        'OPTIONS': {
            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
        },
    }
}

 

4.2、__init__文件中，引入pysql来代替mysqldb

import pymysql
pymysql.install_as_MySQLdb()

5、切换后数据库的生成

将sqlite数据库切换成mysql之后，原先的数据都没有了，需要重新生成数据。

生成相对应的数据库表