Defining the Data Model & accessing the database

Defining the data Model

One, the Django definition data model in the app's models.py file, the database table name is defined in the form of a class:

[Email protected] web]# cd/opt/python/django/web/blog/[[email protected] blog]# vim models.pyfrom django.db Import Mode ls# Create Your models Here.class Host (models. Model): hostname = models. Charfield (max_length =) IP = models. Ipaddressfield ()

Second, check the model syntax and logic is correct: Python manage.py validate, 0 errors no syntax error

[Email protected] blog]# cd/opt/python/django/web[[email protected] web]# lsblog db.sqlite3 manage.py web[[email Prot ected] web]# python manage.py validate0 errors found

III. Management Database

Initialize the data model to the database: Python manage.py syncdb (the Slqite database used by default, as setting.py can see)

[[email protected] web]# cd /opt/python/django/web/web/[[email protected] web]#  vim settings.pyimport osbase_dir = os.path.dirname (Os.path.dirname (__file__)) #base_ Dir is the parent directory of the parent directory of seting.py:/opt/python/django/web/databases = {     ' default ':  {         ' ENGINE ':  ' django.db.backends.sqlite3 ',          ' NAME ':  os.path.join (base_dir,  ' db.sqlite3 '),     }} If the installation is sqlite[[email protected] web]# cd  /opt/python/django/web/[[email  protected] web]# python manage.py dbshellsqlite version 3.6.20enter  ". Help"  for instructionsEnter SQL statements terminated with a  ";" sqlite> .tablessqlite> .exit# Background Demo Database creation process when synchronizing the database,[[email protected] web]#  python manage.py sqlall&Nbsp;blogbegin; create table  "Blog_host"   (     "id"  integer NOT NULL  primary key,     "hostname"  varchar ( NOT NULL,   )   "IP"  char ( not null); COMMIT; #同步数据库, create a table blog_host, create an administrative user [[email protected] web]# python manage.py syncdb   CREATING TABLES&NBSP, ..... Creating table django_admin_logcreating table auth_permissioncreating table auth _group_permissionscreating table auth_groupcreating table auth_user_groupscreating  Table auth_user_user_permissionscreating table auth_usercreating table django_content _typecreating table django_sessioncreating table blog_hostyou just installed  django ' S auth system, which means you don ' t have any  superusers defined. Would you like to create one now?  (yes/no): yesusername  (leave blank to  use  ' root '): root   #创建管理用户Email  address: [email protected]        # Enter the administrative user's mailbox password:                                      #输入管理用户的密码Password   (again):  superuser created  SUCCESSFULLY.  INSTALLING CUSTOM SQL&NBSP, ..... INSTALLING INDEXES&NBSP, ..... Installed 0 object (s)  from 0 fixture (s) [[Email protected] web]# ll Total dosage  48drwxr-xr-x 3 root root  4096 1 Month    3 09:50  Blog-rw-r--r-- 1 root root 34816 1 Month    3 10:12 db.sqlite3    #大小不为0-RWXR-XR-X 1&NBSp;root root   246 1 Month    1 23:11 manage.pydrwxr-xr-x 2  root root  4096 1 Month    3 10:02 web

Iv. Accessing the database:

Method One: command-line access

[email protected] web]# python manage.py Dbshell

Method Two: Manage the database via admin page

1, Qi Gong django[[email protected] web]# nohup python manage.py runserver 11.65.140.13:8080 &2, access in Chrome browser: Enter the user name root and password, the default is not to see the database

You need to register the table with the admin.py admin to recognize

[Email protected] blog]# cd/opt/python/django/web/blog/[[email protected] blog]# vim Admin.pyfrom django.contrib Import adminfrom blog.models Import Host # Loads the app models# Register your models here.class hostadmin (admin. Modeladmin): List_display = [' hostname ', ' IP '] #固定属性, fields similar to table Admin.site.register (host,hostadmin) # Register two tables, refresh the page, one more hos T column, click Add a host, enter the hostname and IP, click Save, more than one host, you can view

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To view a table using the command line

[[email protected] blog]# cd /opt/python/django/web/[[email protected] web]#  ll Total dosage  52drwxr-xr-x 3 root root  4096 1 month    3 10:28  blog-rw-r--r-- 1 root root 34816 1 Month    3 10:32  Db.sqlite3-rwxr-xr-x 1 root root   246 1 Month    1 23:11  MANAGE.PY-RW------- 1 root root  2125 1 Month    3 10:37  nohup.outdrwxr-xr-x 2 root root  4096 1 Month    3 10:02  web[[email protected] web]# sqlite3 db.sqlite3 SQLite version  3.6.20enter  ". Help"  for instructionsenter sql statements terminated with  a  ";" sqlite> .tablesauth_group                   auth_user_user_permissionsauth_group_permissions      blog_host                  auth_permission              django_admin_log           auth_user                    django_content_type        auth_user_groups             Django_session            sqlite> select  * from blog_host;1|132|112.65.140.132sqlite>.exit[[email protected] web]#  python manage.py dbshellsqlite> .tablesauth_group                   auth_user_user_permissionsauth_group_permissions       blog_host                  auth_permission              django_admin_log          auth_user                    django_content_type        auth_user_groups             django_session   sqlite> select * from blog_host ; 1|132|112.65.140.132

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Defining the Data Model & accessing the database