What is Entity Framework ?

Entity framework is an Object/Relational Mapping (O/RM) framework. It is an enhancement to ADO.NET that gives developers an automated mechanism for accessing & storing the data in the database and working with the results in addition to DataReader and DataSet. It eliminates the need for most of the data-access code that developers usually need to write.

It allows you to create a model by writing code or using boxes and lines in the EF Designer. Both of these approaches can be used to target an existing database or create a new database. It also provides services like change tracking, identity resolution, lazy loading, and query translation so that developers can focus on their application-specific business logic rather than the data access fundamentals.

Following figure shows the overall architecture of the Entity Framework (Source : http://www.codeproject.com/)

Application : Application which is going to use Entity Framework.

EDM (Entity Data Model): EDM consist three main parts- Conceptual model, Mapping and Storage model.

• Conceptual Model: Defines model classes and their relationships.
• Storage Model: It is your database design model which includes tables, views, stored procedures and their relationships and keys.
• Mapping: Mapping consist information about how your conceptual model is mapped to storage model.

ADO.Net Provider: This layer communicates with database using standard ADO.Net.

Data Store : Type of database that you are going to use.

Below are the few Step-by-Step tutorials which will give you the better understanding of Entity Framework :

1. Entity Framework : How to create database using code.
2. Entity Framework : How to create code using Existing Database
3. Entity Framework : How to generate model using Entity Framework Design

How to set permanent IP in Ubuntu ?

Steps :

*) Open the interfaces file :
          sudo vi /etc/network/interfaces

If you are using DHCP you will see the following lines :
          auth eth0
          iface eth0 inet dhcp 

*) To make it static, Change the line iface eth0 inet dhcp to iface eth0 inet static and add the following just below it:

address 10.35.34.209 (IP address that you need to set)
netmask 255.255.255.0 (Default mask which in this case is the default class c subnet)
gateway 10.35.34.1 (Typically your router’s IP address)
network 10.35.34.0 (The network that this machine is running on)
broadcast 10.35.34.255

Here is a screenshot of how it should look below :

*) Once you save this file you need to restart your networking service.
       sudo /etc/init.d/networking restart
or
       sudo service networking restart

Note : /etc/init.d/networking restart command is deprecated on new debian and ubuntu, So in such case you can use :

            ifdown eth0 && ifup eth0

How to connect via SSH (putty) to your vmware machine (Ubuntu) ?

It was really a pain for me to work on Oracle VM, It won't allow you to use mouse or do copy-paste. So I decided to connect my local VM via SSH( Putty).

Steps :

1.  In your VM box, Goto Settings -> Network ->Adapter 1 and select "Bridged Adapter"

2. In your Ubuntu Machine, Install "openssh-server" 

          sudo apt-get install openssh-server

3. Reboot the VM and Run "ifconfig" command in terminal and get "inet addr" of "eth0".

4. Open putty, Enter the IP address(IP of your VM machine ) , Select port as "22" and connection type as "SSH" and click on open button.

5. Enter your credential and you are done :)