Django-Marathon 2/6

Django Vs ___________ ?

• MVC: Asp.net MVC
• Django create forms in predefined form layout and need tweak to modify
• Routing is done by controller in asp.net in Django do using expression

Create Project using Django-Admin :

django-admin startproject app-name folder-name django-admin startapp app theapp // theapp is name of folder \Add  app created in  settings.py

What  is Model  : MVC controller Diagram ?

• Data

  regarding data as per projects

• Model  : Class for project , prevent sql injection attacks if using models

ORM:. Object relational mapping

• - Converts queries into SQL
• - Converts results into objects

Implementation of ORM

• - Hibernate in Java
• - Entity Framework in LINQ
• - Django

Save , Delete & Update queries are managed by Django Framework contained in (models.Model)

Properties: size,datatype,Nullability

- Syntax property_name=models.Type(parameters)

-  Eg name=models.IntegerField(null/default/blank/max_length)

Primary Key is added automatically else :

Foreign Key  Syntax

Artist=models.ForiegnKey(Artist) // Automatically map columns to object

• Use (name_name instead of nameNAme ) for models to help out  in Autogenerated forms

For field options in Django

https://docs.djangoproject.com/en/1.10/ref/models/fields/

What database Django Support ?

• - SQLite (default in settings.py)
• - MySQL
• - Microsoft SQL Server

How to create Database ?

• - Makemigrations : create package and send to database
• - Sqlmigrate : display sql statement done by migrate
• - Migrate: take the package and create database

Command for Migration

- python manage.py makemigration  –name migration_name  app

- python manage.py showmigrations app  [to show all migrations done yet  ]

- python manage.py sqlmigrate app  0001_initial [to sql command generated ]

- python manage.py migrate

- python manage.py app  migrate app 0001_initial