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SQL Basic Commands

18 Dec

SQL -> Structured Query Language

SQL lets you access and manipulate databases

Command functions

* SELECT – extracts data from a database
* UPDATE – updates data in a database
* DELETE – deletes data from a database
* INSERT INTO – inserts new data into a database
* CREATE DATABASE – creates a new database
* ALTER DATABASE – modifies a database
* CREATE TABLE – creates a new table
* ALTER TABLE – modifies a table
* DROP TABLE – deletes a table
* CREATE INDEX – creates an index (search key)
* DROP INDEX – deletes an index

SELECT Syntax
SELECT column_name(s) (Type the name of the column)
FROM table_name (Type the name of the table)

DISTINCT Syntax
SELECT DISTINCT column_name(s)
FROM table_name

WHERE Syntax
SELECT column_name(s)
FROM table_name
WHERE column_name operator value

INSERT INTO Syntax
INSERT INTO table_name (column1, column2, column3,…)
VALUES (value1, value2, value3,…)

UPDATE Syntax
UPDATE table_name
SET column1=value, column2=value2,…
WHERE some_column=some_value

DELETE Syntax
DELETE FROM table_name
WHERE some_column=some_value

(example)
DELETE FROM Car (Table name)
WHERE LastName=’City’ AND FirstName=’Honda’

INNER JOIN Syntax
SELECT column_name(s)
FROM table_name1
INNER JOIN table_name2
ON table_name1.column_name=table_name2.column_name

LEFT JOIN Syntax
SELECT column_name(s)
FROM table_name1
LEFT JOIN table_name2
ON table_name1.column_name=table_name2.column_name

RIGHT JOIN Syntax
SELECT column_name(s)
FROM table_name1
RIGHT JOIN table_name2
ON table_name1.column_name=table_name2.column_name

FULL JOIN Syntax
SELECT column_name(s)
FROM table_name1
FULL JOIN table_name2
ON table_name1.column_name=table_name2.column_name

PRIMARY KEY
CREATE TABLE_NAME
(
Column_name1 int NOT NULL PRIMARY KEY,
Column_name2 varchar(255) NOT NULL,
Column_name3 varchar(255),
Column_name4 varchar(255),
Column_name5 varchar(255)
)

FOREIGN KEY

A FOREIGN KEY in one table points to a PRIMARY KEY in another table.

CREATE TABLE_NAME
(
Column_name1 int NOT NULL PRIMARY KEY,
Column_name2 int NOT NULL,
Column_name3 int FOREIGN KEY REFERENCES Table_name1.(Column_name1)
)

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THE MAC TABLET PC-POWERED BY APPLE

18 Aug

apple tablet

No words to describe this note book from apple its just out of imagination.An imagination brought in to reality by apple a note book with a thickness of just 0.38(8mm) and resolution of 2540 Lines Per Inch .
applemactablet

It has all kind of features like Wireless, Text-To-Speech, PDF support.And according to the report suggests that Foxconn will manufacture the new device.No need for a Keyboard, this futuristic device will feature a pen and handwriting recognition ,the touch screen of this new device will lift the new Apple tablet in the ever-popular NOTEBOOK market.
apple

And it is expected that the price of this gadget will be around $500-$600.It is expected that apple will release this by october and create it’s own cpu design.Mac tablet is truly a revolution and surely will be the next generation pc.
apple-style-mac-tablet

Microsoft-Windows 7

6 Jul

windows_7_preview

Vista didn’t really do Windows brand any justice and Microsoft have responded with promising a release or a new operating system in 2009 – Microsoft Window 7. There are loads of benefits to this new system and from looking at the Beta it seems to fix a lot of the problems with Vista. Some of the new functions to look out for:

* Improved task bar with full screen preview.
This has always been a problem with users who open on average of 7 – 15 windows at once. I love the invisible window option.
* Jump Lists
A nice convenient way to reach recent files or files you want to access often.
* New User Interface
There is a bunch of new copy and paste features, more open, re-size, close, maximise, arrange windows options – but it still has the familiar windows style (in fact it does look branding wise just like Vista).
* Internet Explorer 8
Mozilla 3 is currently my choice of browser having lost my patience with IE7 and memory issues. IE7 is still much quick at opening that Mozilla but the overall experience isn’t as good. IE8 plans to fixs this and pull back some of the market share it is losing. Some new functions to look out for with this release are;
o Accelerators
Highlight text or info from a page and select from a number of online services like address look up and
o Webslices
Which monitors changes to websites like weather, sport scores etc.
* Improved Device Management
A single device windows to manage all devices on a computer and Device Stage which allows you to interact better with devices seeing it’s status and run common tasks.
* Home Group
Home groups is a easy way to setup a home network. Microsoft has managed to make this extremely simple to share files, videos or music but with more security.
* Faster and increased performance
* Extended battery life for laptops and portable devices
* Action Center to sort problems easier
* Windows Touch
After all Microsoft’s work on their touchscreen devices and tables of recent this should be a great feature albeit I think devices that start using this will take a while to appear. The problems with touch screens like the Eee PC is that your arms starts to ache after extended use – but it is great for quick tasks like selecting a film, sending an email or checking some news.
* Improved Voice and Handwriting recognition

This should start appearing mid 2009 and I hope to see Windows 7 SP1 (Service Pack) out by the end of the year – just in time for Christmas when gadget and electronics sales are up again

Modem & Router set up

3 Jul

Most of us have a brief idea about how to connect a modem to a computer.The connections that involve with in a modem are very simple and router connection appears to be complicated but its simple too.The connections in a modem are as follows

1.At the back of the modem there will be four ports Dsl,Usb,Ethernet,Power port . Ethernet is the port from where a wire should be hooked up to the computer,in case if we decide to use a usb we can avoid ethernet cable instead of which the usb cable plays the role of the ethernet cable

Power port is the one where the power chord should be connected.The dsl port is the one where the wire from the splitter / filter (or) from the wall jack will be connected ,we can easily distinguish between a ethernet wire and dsl wire from the thickness.Ethernet cable will be a little bit thicker than the dsl cable and the port size of ethernet will be bigger than that of dsl.

siemens

siemens

dsl

2.Incase if you want to connect a router along with the modem.The setup is not so difficult ,the only change that you are gonna do is that the ethernet cable from the modem that is plugged into the computer should be instead plugged in to the back of the router and apart from the port where you plug in the ethernet cable there will be other ethernet ports in the router from where a new ethernet cable should be hooked up and it should be connected to the back of the computer.We can connect up to five to six computers to the internet using a router through wired and wireless method. Thats all about it we are done with the connections and once these connections are done properly we can get connected to the internet “provided your ISP provides you proper internet connection :-)”

Video explaining the connection

Recruitment of Junior Telecom Officers-BSNL

24 Mar

BSNL is going to recruit 3945 Junior Telecom Officers by keeping an exam on 21.06.2009.The 3945 seats are seperated in to three divisions 3545 seats are allocated for junior telecom officers telecom ,200 seats are allocated for junior telecom officers civil and 200 seats are allocated for junior telecom officers electrical.

The pay for this is job is between Rs. 9850-250-14600.3% of the total vacancy will be reserved for PH quota.
The educational qualifications for Junior Telecom Officers telecom are-
The applicant must have completed Bachelor of Engineering/Bachelor of Technology or equivalent Engineering degree in the following
i. Telecommunication,
ii. Electronics,
iii. Radio,
iv. Computer,
v. Electrical,
vi. Information Technology

The educational qualifications for Junior Telecom Officers civil are-
Bachelor of Engineering in civil from a recognized Institution/University.

The educational qualifications for Junior Telecom Officers electrical are-
Bachelor of Engineering in electrical from a recognized Institution/University.

The examination fee is Rs.750 and it should be paid through demand draft only.

The last date for applying for this post is on 06.04.2009.The question paper will be of objective format and the duration is for three hours,Only Indian Nationals would be eligible to apply for these posts.