Is 3 tier architecture and MVC same?

Today, Rishan (sommohon) ask me this question while chatting with him. I gave him the answer in one sentence but I myself was not satisfied with the answer. I thought I should write something about this in short.

After a long period I am writing to my blog. As I am in vacation right now at last I got some time to write something. I can continue writing if you guys help me by requesting topics to discuss and also post reply to this topics.

Now what is the answer.

If you say yes, I think that is correct. If you say no, I think that is also correct. You wonder how? Let’s see the simple similarities and dissimilarities.

Both n-tier architecture and MVC have the same root, or same basic idea that they separate the responsibilities among different parties to make your application more robust, more flexible, more scalable and easier maintainable.

MVC is a design pattern for GUI. A design pattern shows us how to separate responsibilities between VIEW and DATA at the presentation tier. Most web application framework is based on the MVC pattern (MVC Model 2).

N-tier architecture is about how to design your application or system architecture pattern, the basic idea is to separate the responsibilities among different tiers (Presentation tier responsible for UI or User Interface, BL or Business Logic tier responsible for business logic, DAL or Data Access Layer tier responsible for data, Service layer for Service etc.)

So about MVC and N-tier we can say that concepts are same but implementation is different. This is my simple understanding.

I hope to learn and write about this more. Any comments or suggestions?

[Google Tips]: Use Gmail as a Hard Drive

Gmail is providing you more than 2 GB space. So, why not to use this space? You can use Gmail as a network drive on your PC. Yes!

It looks and feels just a regular hard drive. And it’s as simple to use as you might hope, if you are Windows user.

Go to http://www.viksoe.dk/code/gmail.htm and download a copy of GMail Drive. After downloading extract and install the files. You will see a GMail Drive in your My Computer. Click on that drive and you will be prompted for login as show in the picture:-

Copy and paste your files from your local hard drive to GMail Drive.

And your files will appear in your gmail inbox as mails.

Happy GMailing to all Googlians!

Rickshawala

I usually travel by bus while returning from office. There are two ways to return from my office to home. There is a direct bus service from Gulshan-2 to Mohammadpur. And another way is to take 27 no bus from Kakoli upto Asad gate then the rest to Mohammadpur by Rickshaw. My office is at Banani 27 no road, middle of Gulshan 2 and Kakoli.

Yesterday I took the second way. From Asad gate I took a Rickshaw. I rode on the rickshaw and asked the rickshawala, ‘What is the fare upto Mohammadpur Shiya Mosque?’

’15 taka’, he replied.

‘It should be 12 taka, why you are charging more?’

‘If you compare the fair with the previous days then it is not fair. In previous we had to pay 25 taka per day to the owner and now we are paying 80 taka per day’

‘I see. The government set fixed charge for the taxi owners and did not set any constraint for the rickshaw owners’

‘The owners are not responsible for this. They have to buy a tire for 250 taka while they bought it for 150 taka in the past.’ – Rickshawala’s quick reply

I was astonished hearing the rickshawala saying on behalf of the rickshaw owners. I guessed that he himself is the owner and asked the rickshawala to be sure.

‘Hey, stop. Are you the rickshaw owner?’

He smiled, looked at me and said ‘yes sir, I have only one rickshaw’

Who does not like to speak for himself?

SEO Tips

What *NOT* to do?

Don’t submit multiple URLs to Google database for the same site. e.g. mysite.com and mysite.com/index.html are two different URLs.

Don’t do cloaking. Cloaking is a way to keep two different pages. One is optimized for the search engine another is optimized for user.

Doorway pages are another way of cloaking. This is the trick to fill your home pages with keywords and keeping a link for user optimized page.

Hidden texts and hidden links with same color as page background color are often used in doorway pages and are cause to ban from search engines.

Read the rest of this article...

Don’t link bad neighborhood as link farms that may cause to be banned.

Don’t send unsolicited commercial emails called spamming from your site.

Selling advertising in form of links in your site is acceptable but selling PR which will boost another sites PR is not.

Multiple identical pages with very similar content and interlinking them are forbidden.

Multiple domains that redirect to same site and also creating multiple domains that contain almost same content are not allowed.

Google recommends not having more than 100 links in a page. Excessive links will not ban you but will cause a low PR.

Search Engines and the Directories

Directories are searchable database of web sites that are reviewed, selected and categorized by human beings. On the other hand a search engine crawl the web by following the links from webpage to webpage and website to website. You don’t even need to submit your site to a search engine in order to find your site and indexing for searching.

Important directories

Yahoo – most popular but costs $299 and paying is not guaranteed to be included in the top 10 listings

ODP – Open Directory Project, Suggest your site there. Now! This causes your site to be listed in Google

Lycos – popular but again will cost $39

Search Engine Spiders

Spiders crawl from web site to web site by following the links.

Googlebot – 216.xxx.xxx.xxx, monthly deep crawl in the database

Freshbot – 64.xxx.xxx.xxx shallow crawl

Search in Google for your site url, then click on cache for viewing the last cached view of your site by Google

Search Engine Friendly Site: How to

Meta tags –

Title – Choose a meaningful title that reflects your business and cover 2 or 3 keywords. E.g.: ABC Software, the best software development company in Bangladesh.

It contains 3 important keywords regarding your company, best, software and Bangladesh.

Description – Another important Meta tag. It should not contain just a list of keywords but a logical sentence that will contain your keywords. E.g.: ABC Software, a world class software development company, special in desktop based applications.

It contains your keywords and reads like a coherent sentence also.

Links at home page – try to keep all pages link in the home page and also keep a sitemap and link it to home page. So that spiders can follow your whole site with maximum of following 2 links.

Header Tags and ALT Tags –

Near the top of your page you should keep your important keywords in a <H1> tag. Google gives extra weight to text located at header tags to calculate PR. Also use a couple of <H2> tags. E.g.:

<H1>ABC Software: No 1 Software Development Company in Bangladesh </H1>

<H2>we provide 24/7 support to our customers</H2>

Photos will not help your ranking but you can use <ALT> tags to describe the photo and keep 1 or 2 keywords there. Be sure that <ALT> tag is describing your photo. E.g.:

<img src=”wo.jpg” ALT=”Web Office: Web based office management system, one of our best software”>

Add shorter pages to your site

Always try to add new pages to your site. Each a day, If you cannot add each a day then add whenever you can, but don’t add junk

Make shorter pages

If you have longer pages break them and make them shorter

Better Search Engine Rankings for existing site

1. Remove all bad techniques as described earlier


2. Change your title and description to a keyword rich format


3. Add lots of unique keyword rich contents to your pages


4. Reciprocal Linking: Get a few websites (at least 3 or 4) to link to your site. But be very careful about the bad neighbors as discussed earlier.
   

Google Page Rank (PR)

A web page’s Page Rank is a number from 1 to 10 as calculated by Google for that page. The PR value is basically what Google deems to be the importance of your page when compared to other web pages in your category.

The higher PR you rank the better for your site to be top listed. For competitive category sites 5 is a good PR.

Maximize your web pages’ PR: How to

1. Your pages should contain unique original contents that are not replicated in another site and not just like affiliated links


2. Keyword density: you should have your main keywords as much as possible in your page title and description as well as scattered throughout the text of your page while still make sure that the pages are readable, interesting and have the ability to sell


3. No of Visitors will increase your page PR


4. Incoming Links to your page from other web pages: most important


5. Header tags and ALT tags as described earlier
   

Links and their efforts on Page Rank

Tomorrow

How to use MySQL Aggregate Function GROUP_CONCAT()

Few days ago, I got a mail from one of my friend. The mail was asking a question like below:-

Answer the following question within 10 sec and without the help of a calculator.

If 1 = 5, 2 = 25, 3 = 625, 4 = 390625, then 5 = ?

Answer is hidden here

Do you think the answer is (390625)²? No. The answer is 1. Notice the first statement 1 = 5.

I asked this question to some other friends. They also replied the wrong answer. The answer is very simple. But sometimes we make complex and wrong solutions of simple problems. This happens due to lack of proper understanding the 'system'.

Here is similar problem, which occurs frequently in our day to day programming.

Let you have team_member table data like below:-

Read the rest of this article...

id	team_id	fname	initials	last
1	1	John		Smith
2	1	Irin	E	Adler
3	1	Michael		Angelo
4	2	Alan		Border
5	2	W	J	Akram

Now you want a report, which will show each team members in a row.

The simple and optimal solution is to use MySQL GROUP_CONCAT() function. MySQL GROUP_CONCAT() aggregate function is a small handy tool to solve this type of problem. This will simplify big efforts to a small piece of work. To see the above output using the power of MySQL GROUP_CONCAT() aggregate function, use the following query:-

mysql > SELECT team_id AS Team, GROUP_CONCAT( CONCAT( last, ', ', fname, ' ', IFNULL('',initials)) ORDER BY last ASC SEPARATOR '; ' ) AS Members FROM team_member GROUP BY team_id ORDER BY team_id ASC;

The output will be like below:-

Team	Members
1	Adler, Irin E; Angelo Michael; Smith, John
2	Border, Alan; Akram, W J

MySQL GROUP_CONCAT() aggregate function is available from version 4.1.

To learn more, have a look at MySQL reference manual. http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html

You also must know about the MySQL global variable group_concat_max_len. There was a bug regarding this variable which was fixed in a later version 5.0.19. More …

I hope to continue finding the simple and optimal way of problem solving.

Cheers

Ron