Q1.  What is the output if code snippet 3 is executed (consider definitions of code snippet 1 and code snippet 2 too to find your answer)?

interface IA


{
        void Goto();
}

class mybase

{
       void Goto()
        {
               Console.WriteLine("inside mybase constructor.");
        }
}

What is the output of the following code block ?

class  myderived: mybase, IA
{
        
}

a) Does it compiles successfully? or Does it throw any error?
b) Do we need to provide definition of method Goto() in class A()?

Q2. Do we need to define method named Goto() in class "myderived"? or that is not needed ? consider following code?



interface IA
{
        void Goto();
}
interface IB
{
        void Goto();
}
class  mybase
{
        public void Goto()
        {
            Console.WriteLine("inside mybase constructor.");
        }
}
class  myderived: mybase ,IA
{
       //    Does this code compile and run successfully?      
}


a)  Does this code compile and run successfully?      
b) What happens if the keyword "public" is removed from Goto() method defination in "mybase" class?
c) What happens when in interface "IB", the signature of the method "void Goto()" is changed to some other say "int Goto()" keeping everything same? Does "myderived" is compiled successfully or it throws any error?

How To Drop Already Created Index in a sdf file(SQL CE)

Today I had to delete an index already created in a table in a SQL CE database, i.e in a sdf file.
The problem of deleteing/droping an already created index in a table in sdf file is that (1) if you have opened it in SQL Server 2005 editor or (2) using Visual Studio editor, you can not just delete/drop the index though both editor provides you an option for deleteing / droping using content menu item.

The bottom line is, you just can not delete/drop an already created Index in a table in sdf file using either SQL Server 2005 editor or Visual Studio editor.

An already created Index in a table in sdf file can only be dropped/deleted using a query as explained following,
=========================================================

DROP INDEX "TABLE_NAME"."INDEX_NAME"

Where "TABLE_NAME" is the name of the table to which index belong to.
"INDEX_NAME" is the name of the already created index which we want to delete/drop.

=========================================================

Example : If you have a table named "CUSTOMER_POSM_REQUEST" and already existing Index name is "RECORD_ID_INDEX" then as mentioned above, the query would be like this:

DROP INDEX CUSTOMER_POSM_REQUEST.RECORD_ID_INDEX

=========================================================

Use the above query and run the query in either of the editor mentioned above. Index will be deleted. Not sure what is the reason behind that. Need to dig it further :)

Microsoft Interview Questions

1. Consider following code block,
-------------------------------------------------------------
public class A
{
public A()
{
B objB = new B();
Console.WriteLine("A constructor.")
}
}

public class B
{
public B()
{
A objA = new A();
Console.WriteLine("B constructor");
}
}

static void main()
{
A objNewA = new A();
}

---------------------------------------------------
Q: What would be output of the above code when executed? (C# code)

2. What is ASP.NET pipeline?

3. Say you have a milion of record need to be cached for your ASP.NET web application. What would be available options for caching mechanism considering fast access and critical data?

4. In case your answer is "StackOverflow exception happens" for question number 1, then tell us why exception type is "StackOverflow" because as it is seen in the code, that both A and B's constructors are creating new instances of type A/B and new objects are stored in "heap" and not on "Stack". Why it is still then "StackOverflow exception"????

There are couple of more questions too. But I need to memorise it. I would post them as soon as I remember and frame it correctly.

Happy reading !!!!

Cheers,

VC++ in VS 2008 - Part 2- Adding a cpp file having code

After my first small "class A" program in VS 2008, I moved forward to add the same code in a separate file and to access/call that class object in my main program file. I want to mention that I have added a new cpp file by right clicking on the solution and then Add -> New Item -> C++ file(.cpp). I have given my newly added cpp file as "A.cpp".

Therefore I have(1) "VCApp.cpp" having "main" function. (2) "A.cpp" is new file name where I want to add my class A. And then I want to access that class in my main function.

Following is my defination of class "A" which I want to put in "A.cpp"

public class A{
public:
A()
{
Console::WriteLine("Inside A constructor.");
};
};

and I access the class A in my main function as following way ,


int main(array ^args)
{
A* o = new A();
return 0;
}

I put above code and while building, found following compile time error(s),
----------------------------------------------------------------------------------
fatal error C1010: unexpected end of file while looking for precompiled header. Did you forget to add '#include "stdafx.h"' to your source?
error C2065: 'A' : undeclared identifier
error C2065: 'o' : undeclared identifier
error C2061: syntax error : identifier 'A'
----------------------------------------------------------------------------------
To get around of this error (1) Add the following line in A.cpp at the top of it.
#include "stdafx.h"

(2) Add the following line to the top of "VCApp.cpp" file,
#include "A.cpp" ---- adding this line helps compiler to refer defination class A to find in "A.cpp" file.

Now if I compile the code then there is no compile time error and I got following out put in my console output,

Inside A constructor.
Press any key to continue . . .

Happy coding !!!

Exploring VC++ in Visual Studio 2008

Last couple of day I had been thinking of doing some hands on C++. So I have my VS 2008 editor and I leaverage the facilities out of it and started my C++ coding ( After many a years ... possibly after graduation days !!!)

I created a new Project from File->New ->Project -> CLR Console Application then I gave a name "VCApp".

In the project solution I can see that "VCApp.cpp" is the file where I can add my code/any custom written class.

When I have added a custom class named "A". Following is my code for my custom class,


public class A
{
public:
A()
{
Console::WriteLine("Inside A constructor.");
}
}

Though above is a very simple code snippet I was surprised to see following compile time errors
---------------------------------------------------------------------------------------
error C2628: 'A' followed by 'int' is illegal (did you forget a ';'?)
error C3874: return type of 'main' should be 'int' instead of 'A'
error C2664: 'A::A(const A &)' : cannot convert parameter 1 from 'int' to 'const A &'
---------------------------------------------------------------------------------------
I just did a quick inspection in my code then then found that code needs the scope termination operator ";" in proper places. So I modified as following ,

public class A{
public:
A()
{
Console::WriteLine("Inside A constructor.");
};
} ;

Just added a semicolon (1) while closing at end of constructor and (2) End of class and I found the build was succeeded.

The value violated the integrity constraints for the column.

I was trying to import data from one database server table to another database server table when I was getting this error message

SQL SSIS data import wizard error: "
The value violated the integrity constraints for the column.".(SQL Server Import and Export Wizard)"

After several times of troubleshooting to fix the problem and to import data successfuly I have noticed that there one was column in the source table which marked as "NULL" but the same colun in destination table was marked as "NOT NULL". Which caused the error.

Therefore what was happning ,some null value was getting inserted in NOT NULL column which SSIS does not allow and throws an exception saying integrity constraint would be violated.

Sample Query In TOAD using a 'date' variable:
====================================================================

declare dt date;
pp varchar(100);
begin
dt:=TO_DATE('2008/04/25', 'yyyy/mm/dd');
select CEIL((SYSDATE - 180) - Decode(dt,null,(SYSDATE - 180),dt)) into pp from dual;
dbms_output.PUT_LINE(pp);
end;