This is regarding Design Pattern

Question

1.33/5 (3 votes)

See more:

Hai All

I am new to design patterns could any one help with the sample of "singleton". I am i need sample which will use singleton method. I need a SQL Access handler using singleton method.

Posted 12-Apr-11 2:27am

sacraj

Add a Solution

5 solutions

Solution 1

The MSDN documentation should be of great help if you're trying to implement the singleton pattern in .net:

http://msdn.microsoft.com/en-us/library/ff650316.aspx[^]

Posted 12-Apr-11 2:29am

jim lahey

Comments

Sergey Alexandrovich Kryukov 12-Apr-11 14:17pm

Trivial enough, useful enough. My 5, but this time I like the Answer by Bob more, please see.
--SA

Solution 2

Here is an excellent article regarding the Singleton Pattern.
The author has given various aspects of implementing the Singleton pattern and provides you the best way to use it!
http://csharpindepth.com/Articles/General/Singleton.aspx[^]

Here is another sample from MSDN :
http://msdn.microsoft.com/en-us/library/ee817670.aspx[^]

Good luck!

Posted 12-Apr-11 2:40am

Tarun.K.S

Updated 12-Apr-11 2:43am

v2

Comments

Sergey Alexandrovich Kryukov 12-Apr-11 14:17pm

Same thing: simple and useful enough. My 5, but this time I like the Answer by Bob more, please see. --SA

Tarun.K.S 12-Apr-11 14:54pm

Thanks SA, I had a look. He is right but don't know what's going on in OP's mind.

Sergey Alexandrovich Kryukov 12-Apr-11 14:58pm

"We're not the mind readers" should be a part of many Answers!
--SA

Tarun.K.S 12-Apr-11 15:02pm

Yeah!

Solution 3

You might find this[^] discussion useful.

Posted 12-Apr-11 2:43am

Henry Minute

Comments

Sergey Alexandrovich Kryukov 12-Apr-11 14:18pm

Same thing: simple and useful enough. My 5, but this time I like the Answer by Bob more, please see. --SA

Solution 4

See my answer to this question here: how to open only one instance of class not more than that ?[^]. It follows the singleton pattern.

Best Regards,

-MRB

Posted 12-Apr-11 2:53am

Manfred Rudolf Bihy

Comments

Sergey Alexandrovich Kryukov 12-Apr-11 14:19pm

That's good, too, my 5, but this time I like the Answer by Bob more, please see.
--SA

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

BobJanova · Accepted Answer · 2011-04-12T04:48:00

Some good answers here, but I would answer your question with a question. If you're new to design patterns, how are you so sure you want a singleton to solve this problem? An application could easily want to read from multiple databases at the same time, for instance. It is quite a common beginner mistake to see singletons everywhere where they aren't really necessary, and this might be one of those.

You can make sure you only have one instance by the simple mechanism of only creating one instance. Singletons should be used where it makes no sense to have more than one instance of an object, ever, which is fairly unusual.

Your question is a bit vague and I'm not entirely sure what you mean by a 'SQL Access handler' so perhaps you do need a singleton, and if so, refer to one of the articles linked in the other solutions. But before deciding to use a pattern you should always make sure that it is actually what you need for the problem you are trying to solve.