.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

3-State Logic -- mostly for academic fun

Posted By:      Posted Date: September 02, 2010    Points: 0   Category :Sql Server
Before I start, please understand that I am not criticizing nor asking for any kind of change.  Rather, my purpose is more-or-less idle academic curiosity.  My departure point has to do with this kind of syntax: WHERE x NOT IN (SELECT y FROM anyTable) Specifically, the circumstances in which y is a nullable column. Many of you already know that this kind of WHERE clause should be avoided because of 3-state logic.  3-state logic cause this kind of WHERE clause to exclude all rows whenever there are ANY null values in the y column.  The logic is to interpret a NULL as a state in which the value of y is "unknown".  The logic continues in that since Y is unknown it becomes therefore impossible to decide whether or not X is truely not in the Y column. Fair enoug.  Now, by academic logic and not based on how SQL works if we apply the "NULL represents an UKNOWN value" hypothesis and for the sake of consistency, should the MAX and MIN functions given in this circumstance also be NULL? declare @test table (x tinyint) insert into @test select null union all select 3 union all select 250 --select * from @test select min(x) [Min], max(x) [Max] from @test /* -------- Output: -------- Min Max ---- ---- 3 250 Warning: Null value is eliminated by an aggregate or other SET operation. (1 row(s) affected) */ I am not saying that th

View Complete Post

More Related Resource Links

Truly Understanding View State

This article provides a detailed understanding of the ViewState.

Logic behind N -Tier Application Development

In the arena of application development, developers all over the world use various programming languages, technical processes, and technical tools. While using number of technical & non technical elements the processes or methods become complex, for simplification of the application development process, developers use various techniques such as dividing the application architecture into layers or parts. In the professional & technical language this separation or division process is called N-Tier Application Development process, where "N" stands for number and "tire" stands for layers or parts.

Design Patterns - Using the State Pattern in C#

What is the State Pattern?

The State Pattern is a behavioral pattern that can be used to alter the behavior of an object at run time. As the state of an object changes, the functionality of the object can change drastically. This change of behavior is hidden from the Client and the Client interfaces with a wrapper object known as the Context. The State Pattern is a dynamic version of the Strategy Pattern.

view state vs request parameters


If  the view state is the data entered into the form fields then they are supposed to be available in the request parameters or request body. Then why would we need view state for?


SQL Server Session state problem.


Hi to all,

I have some things that I want to know. I am right now using a free asp.net webhosting ("somee.com"). The problem is that when I am visiting a page, there's a tendency that values stored in my session variables are lost. Therefore, it causes an error when the requested page is loaded.

1. I am thinking of using sessionState mode="SqlServer". Will it solve my problem?

Actualy Im working on it but Im having problems when connecting to the sql database.

2.  Is that a problem in the webhost?

3. Do free webhosting sites provide allow session state in the sql server?. Because ive tried it locally into my computer and error say's i should intall the ASP.NET Session State SQL Server version 2.0 or above.

View State Encryption


Hi All,

Why is it that I see the same hash value generated when I use different algorithms for viewstate encryption. I have added below lines to the web.config file

<pages viewstateEncryptionMode="Always"

browser gives jibberish when State manager (sql) is turned on


Hi all, we're testing our web app with a state manager so that we can do distributed rollouts. We're not getting any errors, but we are getting jibberish returned for every page request. 

(it won't even let me paste it in here)

HOw do I get it to serve the pages normally?


Pattern for huge logic



I am looking for a pattern/way to code for implement Huge logical hierarchy, Basically this is to verify person details like qualification, experience, expertised-in and global region.... and issue certain access for a perion of time.

The verification process has huge number of conditions it took around 1 year to document. And now we have to develop C# to implement it, can any one help me...? a sample code will be appreciated.

Thank you


Custom Server Control Property not maintaining state


I have created a server control consisting of a TextArea and a div under it.  My goal is to create my own asp:TextArea type control.  the div is for a Character count of the text area and seems to work ok but i added a CharacterCountVisible property to the control that is always returning true.  See Proptery definition below


<Bindable(False), Category("Appearance"), DefaultValue("True"), Localizable(True)> Property CharacterCountVisible() As Boolean
        Return _CountBoxVisible
    End Get
    Set(ByVal value As Boolean)
        _CountBoxVisible = value
    End Set
End Property

Note the _CountBoxVisible variable is define inside the class as :

Dim _CountBoxVisible as Boolean = True

What I am trying to do is give the user/coder the option to show/utilize the char count feature.  Can make it disappear with textarea1.CharacterCountVisible = False but setting it to true will not make it display.


What am i missing





Logic to calculate business hours


Hi All,

I have tried searching all over the web for this logic. Got many but half of them did not match what i was looking for and half were malfunctioning.

I want to calculate business working hours between 2 datetime, where in I should be able to set the working hours as well as weekends and holidays should not be calculated.


Please help me guys... It will be a great help... 

Security Briefs: View State Security


Effectively managing user state in web applications can be a tricky balancing act of performance, scalability, maintainability and security. The security consideration is especially evident when you're managing user state stored on the client. Here's what you need to know about view state security.

Bryan Sullivan

MSDN Magazine July 2010

CLR Inside Out: Handling Corrupted State Exceptions


There's a danger in using one-size-fits-all exception handling, and you need to know how to avoid it by being as specific as possible about how you handle errors.

Andrew Pardoe

MSDN Magazine February 2009

Foundations: Managing State With Durable Services


This month Juval Lowy tackles questions such as when to keep proxies and services in memory for better state management in long-running workflows.

Juval Lowy

MSDN Magazine October 2008

WCF P2P: How To Design State Sharing in a Peer Network


Learn how you can peer-enable business applications by allowing them to share state in a serverless peer network.

Kevin Hoffman

MSDN Magazine July 2008

WF How-To: Building State Machines with Windows Workflow Foundation


State Machine workflows represent a different way of visualizing program logic. Rather than flowing from activity to activity like sequential workflows, State Machines transition from state to state. Learn about uses for State machines and see how to design and build a State Machine workflow with Windows Workflow Foundation.

Keith Pijanowski

MSDN Magazine February 2008

Bugslayer: Measuring the Impact of View State


Bloated view state can be a real performance bottleneck for your Web app, but it can be difficult to diagnose. John Robbins creates a handy tool that records and reports the view state size for pages in your ASP.NET applications.

John Robbins

MSDN Magazine November 2007

Extreme ASP.NET: A New Solution to an Old State Storage Problem


State management in Web applications is a contentious issue. Should you store user data per session or should you persist it across sessions? You can easily store information temporarily while someone navigates your site by using session state.

Fritz Onion

MSDN Magazine April 2006

ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend