Tutorial for how to Get started to learn Oracle

Oracle is an object-relational database management system. It allows users to create, maintain, modify, and even erase any and all data and objects within an existing database.

1 You need to download the Oracle XE (Express Edition) to quickly get started with it.
[info]Click here to download the Oracle XE Edition[/info]
[success] Note that Oracle XE is available only for Windows 32 bit, If you have a 64-bit, you may need to install the full version of Oracle[/success]

2 Once you have downloaded the XE version, unzip it and double click on to proceed with the installation.

3 If it is installed successfully, click on Start -> All Programs -> Oracle database 11g Express Edition -> Go to Database Home Page

4 Your browser would be opening an admin page for Oracle to login.  as shown below. The password is the one you have set during the installation.
[info]The username for login is : system [/info]

5 Once logged in inside, you will be having four options. Click on the SQL icon.

6 Afterwards, choose SQL Commands

7 A Page with a textarea to type in your SQL query and execute through clicking run

[info]The SQL command area TAKES ONE SQL COMMAND at a time[/info]

8 Type in the following queries to create a table:  

CREATE TABLE friends (
  friends_id NUMBER NOT NULL PRIMARY KEY,
  name VARCHAR2(100) NOT NULL
);

9 Insert some data into the table now:

INSERT ALL 
INTO friends ( friends_id, name) VALUES ('1', 'Imed') 
INTO friends ( friends_id, name) VALUES ('2', 'Asma') 
SELECT * FROM dual;

10 Search for data using the SELECT command as:

SELECT * FROM friends

Questions

1 How to have an AUTO_INCREMENT attribute for a column in Oracle if possible ?

2 what does it mean : SELECT * FROM dual ?

2 is there a difference between SCHEMA vs Database in Oracle