What is RDBMS



Definition of, what is Relational database management system RDMS, definition of primary key and foreign key, real world example for RDMS, primary keys and foreign key, Structure of Tables in RDMS

What is Data Model or its definition: The data structures and access techniques provided by a particular DBMS are called its data model. A data model determines both the “personality” of a DBMS and the applications for which it is particularly well-suited.

Explained Definition of RDBMS: A relational database (RDBMS) is a database where all data visible to the user is organized strictly as tables of data values, and where all database operations work on these tables. It is based on the relational model proposed by Codd as an attempt to simplify the database structure.

A relational DBMS can represent parent/child relationships, but they are visible only through the data values contained in the database tables. SQL is based on the relational data model that organizes the data in a database as a collection of tables.

Structure of Tables in RDMS: The organizing principle in a relational database is the table, a rectangular row/column arrangement of data values. Each table in a database has a unique table name that identifies its contents.
  • Each table has a table name that uniquely identifies it.
  • Each table has one or more named columns, which are arranged in a specific, left-to-right order.
  • Each table has zero or more rows, each containing a single data value in each column. The rows are unordered.
  • All data values in a given column have the same data type and are drawn from a set of legal values called the domain of the column. 

Tables are related to one another by the data they contain. The relational data model uses primary keys and foreign keys to represent these relationships among tables.
Definition of Primary Keys: A primary key is a column or combination of columns in a table whose value(s) uniquely identify each row of the table. A table has only one primary key.

Definition of Foreign Keys: A foreign key is a column or combination of columns in a table whose value(s) are a primary key value for some other table. A table can contain more than one foreign key, linking it to one or more other tables.

Just as a combination of columns can serve as the primary key of a table, a foreign key can also be a combination of columns. In fact, the foreign key will always be a compound (multicolumn) key when it references a table with a compound primary key. Foreign keys are a fundamental part of the relational model because they create relationships among tables in the database.

Point to Keep Remember in Mind: A primary key/foreign key combination creates a parent/child relationship between the tables that contain them.

Relational Databases with 12 Rules of Codd

Codd’s 12 Rules for Relational Databases
Codd’s 12 Rules for Relational Databases



Relational Databases with 12 Rules of Codd, codd twelve rules for relational databases, real world scenarios for the codd 12 rules  ...

...

SQL Preface



SQL is an inclusive language for interacting and controlling the DBMS or database management system which contains all about forty statements, specialized in database management works. It is a descriptive or declarative language instead of procedural one (Fourth generation language).

Structured English Query Language is its original name provided by IBM, shortened to the acronym SEQUEL. When IBM was discovered that SEQUEL has a trademark owned by the Hawker Suddenly Aircraft Company of the United Kingdom, they shortened the acronym to SQL. The word “English” was then dropped from the spelled-out name to match the new ellipsis.

SQL is used to manage all of the methods that a DBMS provides for its developers, including:

    Data definition SQL lets a user describe the configuration and business of the stored data and relationships among the stored data items.

    Data retrieval SQL allows a user or a function program to recover stored records from the database and use it.

    Data manipulation SQL allows a user or an application software project to update the database by adding new records, removing old records, and modifying previously stored records.

    Access control SQL can be used to restrict a user’s capability to recover, add, and modify record, protecting stored record against unauthorized access.

    Data sharing SQL is used to coordinate record sharing by concurrent clients, ensuring that changes made by one client do not inadvertently wipe out changes made at nearly the same time by another client.

    Data integrity SQL describes integrity constraints in the database, protecting it from corruption due to inconsistent updates or structure failures.

SQL plays following roles also:

    SQL equal to an interactive query language: clients type SQL commands into an interactive SQL program to retrieve record and display it on the screen, providing a convenient, easy-to-use tool for ad hoc database queries.

    SQL equal to database programming language: Programmers embed SQL commands into their application programs to entrance the record in a database. Both client-written programs and database utility programs (such as report writers and records entry tools) use this technique for database right of entry.
    SQL like a database administration language: The database administrator answerable for managing a mainframe or minicomputer database uses SQL to define the database structure and to manage access to the stored record.

    SQL like a client/server language: PC  programs use SQL to communicate over a network with database servers that store shared record. This client/server architecture is used by many trendy enterprise-class applications.

    SQL like an Internet data access language: Internet web servers that interact with business record and Internet application servers all use SQL as a standard language for accessing corporate databases, often by embedding SQL database access within popular scripting languages like PHP or Perl.

    SQL like a distributed database language: Distributed database management systems use SQL to help distribute data across many connected computer systems. The DBMS software on each system uses SQL to communicate with the other systems, sending requests for data access.

    SQL like a database gateway language: In a computer network with a mix of different DBMS products, SQL is often used in a gateway that allows one brand of DBMS to communicate with another brand.

Introduction with SQL, Use of SQL, sql roles in current development, software engineering and another task, DBMS means data base management system,    Data integrity SQL, different -2 features of sql

Anonymous Functions

Anonymous Methods
Anonymous Methods

Pass Arguments and Return a Value from an Anonymous Method
Pass Arguments and Return a Value from an Anonymous Method

 Definition and use of Anonymous Functions methods in c # sharp dot .Net, real world scenarios and live code example for Anonymous Functions methods

Shallow Copy and Deep Copy

Difference between Shallow Copy and Deep Copy

Shallow Copy


Shallow Copy
Shallow Copy

Console.Writeline("oCloneMeTarget - {0}", oCloneMeTarget.oShallowCopy.iValue);  // Output: oCloneMeTarget – 6


Deep Copy


Deep Copy
Deep Copy

Console.Writeline("oCloneMeTarget - {0}", oCloneMeTarget.oDeepCopy.iValue);  // Output: oCloneMeTarget – 10

This time, the contained objects are independent.


Difference between Shallow Copy and Deep Copy, real world scenarios and live code example of shallow copy and deep copy, use of shallow copy and deep copy

Use Of Multicast Delegates


Multicast Delegates (Multicasting)

Multicast Deletages
Multicast Deletages
     string temp = "";
    int i, j;
    for(j=0, i= sTestString.Length-1; i >= 0; i--, j++)
      temp += sTestString[i];
    sTestString = temp;
    Console.WriteLine("Reversed string.");
  }

  static void Main()
  {

    // Construct delegates

    ModifyString oModifyString;

    ModifyString oModifyStringReplaceSpaces = ReplaceSpaces;
  // Method Group Conversion
    ModifyString oModifyStringRemoveSpaces = RemoveSpaces; 
 // Method Group Conversion
    ModifyString oModifyStringReverseString = Reverse; 
 // Method Group Conversion
    string sString = "This is a test for Multicast Delegates";
   
    // Set up multicast
    oModifyString = oModifyStringReplaceSpaces;
    oModifyString += oModifyStringReverseString;
   
    // Call multicast
    oModifyString(ref sString);
    Console.WriteLine("Resulting string: " + sString);
    Console.WriteLine();
   
    // Remove replace and add remove
    oModifyString -= oModifyStringReplaceSpaces;
    oModifyString += oModifyStringRemoveSpaces;
    sString = "This is a test."; // reset string
   
    // Call multicast
    oModifyString(ref sString);
    Console.WriteLine("Resulting string: " + sString);
    Console.WriteLine();
  }
}



Why are delegates used?

All delegates are classes that are implicitly derived from System.Delegate. In general, delegates are useful for two main reasons:

1. Delegates support events.
2. Delegates give your program a way to execute methods at runtime without having to know precisely what those methods are at compile time. This ability is quite useful when you want to create a framework that allows components to be plugged in

Definition, what is Multicast Deletages (Multicasting), real world scenarios and live code example of Multicast Deletages (Multicasting), use of Multicast Deletages (Multicasting)




Delegates

Delegates
Delegates
  public double ComputeInstance( int iValueX, int iValueY ) // instance method

  {
    double dResult = (iValueX + iValueY) * dFactor;
    Console.WriteLine( "Instance Results: {0}", dResult );
    return dResult;
  }
  public static double ComputeStatic( int iValueX, int iValueY ) // static method
  {
    double dResult = (iValueX + iValueY) * 0.5;
    Console.WriteLine( "Static Result: {0}", dResult );
    return dResult;
  }
  private double dFactor;
}

public class MyComputer
{
  static void Main()
  {
    Computer oComputer1 = new Computer( 0.69 );
    Computer oComputer2 = new Computer( 0.76 );
    ComputeOutput delegate1 = new ComputeOutput (oComputer1.ComputeInstance );
    ComputeOutput delegate2 = new ComputeOutput (oComputer2.ComputeInstance );
    // points to a static method - use method group conversion
    ComputeOutput delegate3 = Computer.ComputeStatic; 
    double dTotal = delegate1( 7, 8 ) + delegate2( 9, 2 ) + delegate3( 4, 3 );
    Console.WriteLine( "Output: {0}", dTotal );
  }
}

Method Group Conversion allows you to simply assign the name of a method to a delegate, without usingnew or explicitly invoking the delegate’s constructor.

Computer.StaticCompute is actually called a method group because the method could be overloaded and this name could refer to a group of methods. In this case, the method group Computer.StaticCompute has one method in it.
C# allows you to directly assign a delegate from a method group. When you create the delegate instances via new, you pass the method group in the constructor


What is delegate, use of delegate in c# sharp dot .Net, real world scenarios and live code example of delegate, C# allows you to directly assign a delegate from a method group

Contravariance Vs Covariance

Covariance Vs Contravariance

Covariance Vs Contravariance


  static void Main()
  {
    ArgumentY oArgumentY = new ArgumentY();
    // In this case, the parameter to IncrA is ReturnX and the parameter to ChangeIt  is
    // ArgumentY.
    // Because of contravariance, the following line is OK.
    ChangeIt oChangeIt = IncrA;
    ReturnX oReturnX = oChangeIt(oArgumentY);
    Console.WriteLine("oReturnX: " + oReturnX.iValue);

    // In the next case, the return type of IncrB is ArgumentY and the return type of
    // ChangeIt is ReturnX.
    // Because of covariance, the following line is OK.
    oChangeIt = IncrB;
    oArgumentY = (ArgumentY) oChangeIt(oArgumentY);
    Console.WriteLine("oArgumentY: " + oArgumentY.iValue);
  }
}

The output from the program is shown here:
oReturnX: 1
oArgumentY: 1



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What is an Interface


Definition of an Interface?


An interface provides a specification rather than an implementation for its members. The members of interface will be implemented by the classes and structs that implement the interface. An interface can contain only methods, properties, events, and indexers (an abstract class also precisely contains the same members). An interface is special in the following ways:
  • Interface members are all implicitly abstract. In contrast, a class can provide both abstract members and concrete members with implementations.
  • A class (or struct) can implement multiple interfaces. In contrast, a class can inherit from only a single class, and a struct cannot inherit at all.
Interface members are always implicitly public and cannot declare an access modifier. Implementing an interface means providing a public implementation for all its members:

If a class that implements an interface does not define all the methods of the interface, then it must be declared abstract and the method definitions must be provided by the subclass that extends the abstract class. In addition to this an interfaces can inherit other interfaces.

interface ISum
{
  int iGetSum(int i, int j); //By Default Public
}

class Sum : ISum
{
  public int iGetSum(int i, int j) //Must be declare Public
 {
   return i + j;
 }
}

Definition of an Interface, real world scenarios and live code example for interface, use of interface in c # sharp dot .Net, Interface members are always implicitly public and cannot declare an access modifier

Lambda Expressions in C sharp


Definition and Use of Lambda Expressions in C# .Net

 

Lambda Expressions

Lambda Expressions

 delegate int Increment(int v);

// Declare a delegate that takes an int argument
// and returns a bool result.
delegate bool IsEven(int v);
class SimpleLambdaDemo
{
  static void Main()
  {
    // Create an oIncrement delegate instance that refers to
    // a lambda expression that increases its parameter by 2.
    Increment oIncrement = count => count + 2;
    // Now, use the oIncrement lambda expression.
    Console.WriteLine("Use oIncrement lambda expression: ");
    int iIndex = -10;
    while(iIndex <= 0)
    {
      Console.Write(iIndex + " ");
      iIndex = oIncrement(iIndex); // increase x by 2
    }
    Console.WriteLine("\n");
    // Create an IsEven delegate instance that refers to
    // a lambda expression that returns true if its parameter
    // is even and false otherwise.
    IsEven oIsEven = n => n % 2 == 0;
    // Now, use the oIsEven lambda expression.
    Console.WriteLine("Use oIsEven lambda expression: ");
    for(int i = 1; i <= 10; i++)
    {
      if(oIsEven(i)) Console.WriteLine(i + " is even.");
    }
  }
}

The output is shown here:
Use oIncrement lambda expression:
-10 -8 -6 -4 -2 0
Use oIsEven lambda expression:
2 is even.
4 is even.
6 is even.
8 is even.
10 is even.

Statement Lambda
Statement Lambda

Definition and Use of LambdaExpressions in C# sharp dot net, real world scenarios and live code example forlambda expressions,  introduction to lambda expressions in C# sharp

 


Stack and a Heap in dot Net



Difference in between the between a Stack and a Heap in .Net 

Differentiate between a Stack and a Heap in .Net

Differentiate between a Stack and a Heap in .Net 


a Stack and a Heap in .Net

a Stack and a Heap in .Net



Difference in between the between a Stack and a Heap in dot .Net, real world scenario and live code example for stack and a heap, use of stack and head in asp dot .net c sharp #

Interface



Definition : What is an Interface? 

What is an Interface

What is an Interface

 



interface ISum
{
  int iGetSum(int i, int j); //By Default Public
}

class Sum : ISum
{
  public int iGetSum(int i, int j) //Must be declare Public
 {
   return i + j;
 }
}


Definition , What is an Interface, real world scenario and live code example for Interface, use of interface in programming of asp dot net or c sharp #

Overriding and Overloading



Overriding and Overloading: What is the difference?

Overloading and overriding are different aspects of polymorphism.

Overloading and Overriding: What is the differenc

Overloading and Overriding: What is the differenc




Example:

Base Class:
-------------------------------
public class BaseClass
{
  public virtual void Method1()
  {
    Print("Base Class Method");
  }
}

Derived class
-----------------------------
public class DerivedClass: BaseClass
{
  public override void Method1()
  {
    Print("Derived Class Method");
  }
}

Usage
--------------------------
public class Sample
{
  public void TestMethod()
  {
    DerivedClass objDC = new DerivedClass();
    objDC.Method1();
    BaseClass objBC = (BaseClass)objDC;
    objDC.Method1();
  }
}

Result
---------------------
Derived Class Method
Derived Class Method

difference in between Overriding and Overloading, real world example and live code example on Overriding and Overloading, use of Overriding and Overloading in c sharp #

Abstract and an Interface class

Difference in between an Abstract and an Interface class ...

Differentiate between an Interface and an Abstract class

Differentiate between an Interface and an Abstract class






Difference in between an Abstract and an Interface class, real world scenarios and live example on Abstract and an Interface class, use of Abstract and an Interface class, invoking the Abstract and an Interface class in functions

What is Difference in between as and cast operators

Differentiate between as and cast operators

Differentiate between as and cast operators




What is definition and difference in between as and castoperators, live code or real world example scenario on as and cast operators, use of as and cast operators with c sharp #

Detailed Explanation of Classes

Explain Classes in detail

Explain Classes in detail



Detailed Explanation of Classes
Detailed Explanation of Classes


Detailed Explanation of Classes, Live code or Real world example on Abstract Classes, Static Members, Static Classes, Partial classes, Sealed classes, Abstract Method

Comparison in between is and as operator in C sharp

Differentiate between is and as operator in C#

Differentiate between is and as operator in C#





Comparison in between  is and as operator in C# sharp, live codeexample of is and as operator in C#, real world example for is and as operator in C#, use of is and as operator in C#

Structures in C Sharp

Structures in C#

Structures in C#





Definition of Structures in C#, real world example or scenario of Structures in C#, live code for Structures in C sharp, use of Structures in C sharp, types of Structures in asp .net

out and ref keywords

Differentiate between out and ref keywords



Differentiate between out and ref keywords

Differentiate between out and ref keywords


Differentiate between out and ref keywords, real world example for out andref keywords, live code for out and ref keywords, use of out and ref keywords

Constructor



Constructors


Constructors

Constructors

·  The runtime invokes the static constructor when it creates an instance of the class or before accessing the first static member invoked by the caller.
·  The static constructor executes before any instance-level constructors.

use of static constructor, struct constructor and instance constructor, real world example of 
static constructor, struct constructor and instance constructor, live code for
static constructor, struct constructor and instance constructor

Differentiate between the int and Int32



Differentiate between the int and Int32 datatype, or String and string (lowercase)

Differentiate between the int and Int32 datatype, or Stringand string, real world example of int and Int32 datatype, or String and string, live code of int and Int32 datatype, or String and string

int and Int32 datatype, or String and string

int and Int32 datatype, or String and string

Destructor



What is destructor, how destructor can be used in c sharp #, real world example of destructor, live code of destructor used in programming?

Destructor
Destructor

Difference between Equals Method

Difference between == and .Equals Methods in C # sharp, use of == and .Equals Methods, real world example of == and .Equals Methods in C # sharp, live example of == and .Equals Methods C # sharp 

Difference between == and .Equals Method

Difference between == and .Equals Method

What are Access Modifiers in C Sharp

What are Access Modifiers in C# sharp, public specifier, Protected specifier, internal modifier, Protected Internal, live example of Access Modifiers in Asp .Net, Real world example of Access Modifiers in c# sharp

Access Modifiers in C#

Access Modifiers in C#

Difference between class and struct in C Sharp

Difference between class and struct in C#, real world code for class and struct in C#, real world example of class and struct in C#, class and struct in Asp .Net

class and struct in C# .Net

class and struct in C# .Net

Data Type in C sharp

Data Types Overview
Here we will discuss about the C# tutorial about data types.
Computer programs work with data. Spreadsheets, text editors, calculators or chat clients. Tools to work with various data types are essential part of a modern computer language. A data type is a set of values, and the allowable operations on those values
A data type can be described as being either:
  • A built-in data type, such as an int or char, or
  • A user-defined data type, such as a class or interface.
  • Data types can also be defined as being either:
  • Value Types (C# Reference), which store values, or
  • Reference Types (C# Reference), which store references to the actual data.

    Explain the data types in C#


    Explain the data types in C#
    Explain the data types in C#
    Explain the data types in C#, real world example of data type in c# sharp, live code for data type in c sharp, use of data type in c#

Difference between class and interface in C Sharp

Difference between class and interface in C#
 

Difference between class and interface in C# sharp, live code for class and interface, live example for interface and class, use of class and interface in dot net using c sharp
  
class and interface in C#
class and interface in C#

Const Keyword

The const keyword




What is const keyword, use of const keyword, live code for const keyword,
 live example of const keyword, const keyword in c# sharp

The const keyword
The const keyword
 
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