Women's Day Special

Today, on Women's Day I got a bunch of Beautiful flower, Chocolate and a Sweet Gift from Inforica. It was a Good Surprise for me when I reached office and saw a bunch of flower, chocolate and a gift already kept on my desk, Thank you so much Sudeep for making every Women feel special today, in Inforica.

Today, I Solved some online Sample papers of IBPS Exam just for practice since I  have applied for that Examination and the exam day is coming closer. Apart from this I am doing the Updations that Sudeep told me to do in my GetJob Project. I am done with adding Master page and linking it with the Content pages so that the Title and Menu Control will appear in each page. Now left with some validation part. Will probably complete today.

Normailization in SQL Server

Normalization is a process of minimizing data redundancy with a series of steps called as normal forms.

The total normalization process includes the following normal forms.

• First Normal Form (1NF)
• Second Normal Form (2NF)
• Third Normal Form (3NF)
• Boyce Codded Normal Form (BCNF)
• Fourth Normal Form (4NF)
• Fifth Normal Form (5NF)
• Restrict Union Normal Form (RUNF)
• Project Join Normal Form (PJNF)
• Sixth Normal Form (6NF)

First Normal Form (1NF):  A table is said to be in 1NF if and only if a primary key is defined for that table and the table does not contain any multivalued columns.

Second Normal Form (2NF): A table is said to be in 2NF if and only if the table is in 1NF and no partial dependencies exist in the table.

Third Normal Form (3NF): A table is said to be in 3NF if and only if the table is in 2NF and no transient dependencies exist in the table.

Properties

There are also members of a class using which we can provide access to the value of a class outside of the class.
If at all a class is associated with any values and if we want those values to be accessible outside of the class we can provide access to those values in two different ways.

• By storing value under a public variable we can provide access to that value outside the class but in this case the public variable gives get value or set the value.

       public class Test
       {
       public int x=100;
       }
       Test obj=new Test()
       int a=obj x
       obj.x=100

• By storing the value under a private value also of a class by defining a property on that variable given in three different ways

1. Both get and set access(Read/write/property)
2. Only get access(Read only property)
3. Only set access(write only property)

Syntax to define a property:

      [<modifiers>]<type>[Names]

      {

      [get{statements}]  // Get accessor

      [set{statements}]  // Set accessor

      }

Methods of a 'class' in CSharp

A class is a collection of members, where members of class can be off various kinds like :

• Fields
• Members
• Constructors
• Destructors
• Properties
• Indexes
• Events
• Delegates
• Enum

Destructor: This is also a special method present under a child class same like a constructor but constructor method gets called when object of class is created and destructor is called whenobject of class is destroyed.

   Both constructor and destructor method will exactly have the same name i.e the name of the class which they have. To differentiate between this two we use 'tidle' operation before the destructor method.

class Test

 {

    Test() 

     {

        //Constructors

     } 

   ~Test()

    {

      //Destructors

    }

}

• Destructor methods cannot be applied with any modifirs or parameters.
• Garbage Collector is responsible for destroying the object of class and when the object of class is being destroyed, destructor methods gets called and moreover Garbage Collector can destroy the object of class in any of the following three classes.

1. In the end of a program's execution each and every object i.e associated with the program is automatically destroyed.
2. Sometime in the middle of a programs execution implicit calling of Garbage Collector takes place provided the memory is full that it identifies finds unused object and destroys them.

Exception Handling In SQL Server

Similar to other programming languages SQL server also supports exception handling i.e handles the exceptions, provide a proper message to the user regarding exception and avoid abnormal termination of the program.

Up to SQL sever 2000, a system variable called @@Error is use to get information about the exception and handle the exception but from SQL Server 2005 onwards exception handling is done by using try catch.

Within SQL server,  a try block can have only one catch block.

Syntax:

         begin try

          <statements>

         end try

          begin catch

          <statements>

         end catch

Error Functions

To get information about raised exception a set of functions are provided, which are collectively called as Error Functions are new in SQL 2005.

• Error_Number() : Returns the unique number of raised error.

• Error_Message() : Returns the message associated with the current  error raised.

• Error_Severity() : Returns the severity of the current error raised.

• Error_State() : Returns the state of current error raised.

• Error_Procedure() : Returns name of the procedure in which exception occurs.

• Error_Line() : Returns the line number within the procedure where error occurs.

Geting List of SQL Server error messages:
select * from sys.messages

You can add your own error messages to the error messages list of SQL server using the stored procedure sp_add message.

Raising Errors Manually:
There are situations where system will not raise an exception for your requirement and you want to raise exception manually for this use the riase error function that has following syntax :

raiserror(msgid/msgtext,severity,state[,arguments])

Triggers

      Triggers are stored sub-programs that will be automatically executed based on specified event.

Differences between Stored Procedures, User Defined Functions and Triggers are as follows-->

• Stored Procedures and User Defined Functions can be called by the user manually but triggers cannot be called by the user manually and they will be automatically invoked.
• Stored Procedures can return a value with output parameters and User Defined Functions can return a value with return statement but triggers cannot return a value either with output parameters or return statement.
• Stored Procedures, User Defined Functions can take arguments but triggers cannot take arguments.

Based on event specified on a trigger, triggers are classified into DDL triggers and DML triggers. When the trigger is created by specifying a DDL command as event then that trigger is called as DDL triggers and when a trigger is created by specifying a DML command then that trigger is called as DML triggers. 

     

      DDL triggers are new in SQL 2005. DML triggers have the following three purposes-->

• Create procedure integrity constraints.
• Record auditing information of a table.
• Allow insert,update,delete on complex views.

Access Modifiers

Members that are defined in type by any scope on specific are always accessible within the type. Restrictions comes into picture only when we try to access them outside of the type. Members declared as private under a class or structure cant be access outside of the type in which they are defined and moreover there default scope is private only.

Types cant be declare as private so private can be use only on members. One point to keep in mind is that Interface cant contain any members and default scope for interface members is public.

• Protected: Members declared as protected under a class be accessed only within the class or in a child class.Non child classes cant consume them. Types cant be declared as protected also, so this can only be used on members.

• Internal: Members and types that are declared as internal can be consumed only within the project bot both from child or non child. The default scope for any type in C# is internal only.

• Protected Internal: Members declared as protected will have dual scope i.e within the project they behave as internal providing access to anywhere in project outside the classes they will change to protected and still provide access to their child classes. Types cannot be declared as protected internal also. So this can also be used only on members.

• Public: A type or member of a type if declared as public is global in scope which can be accessed from anywhere.