Archive for January, 2012

Following program is developed using C# in Microsoft console application. It mainly contains 3 classes. Student class used to maintain student info and LinkedList class used to maintain linkedlist of student’s objects. Program class uses both Student & LinkedList class to run and show the required output.

using System;

namespace DataStructures

{

public class Student

{

// Constructors

public Student()

{

}

// Constructor Overloading

public Student(string fName)

{

FName = fName;

}

// Variables

private Student next;

// Properties

public Student Next

{

get { return next; }

set { next = value; }

}

public string FName { get; set; }

public string LName { get; set; }

public string CourseCode { get; set; }

public double Grade { get; set; }

// Methods

public string Display()

{

return “Name: ” + FName + ” ” + LName + ” Course: ” + CourseCode + ” Grade: ” + Grade + “\r\n”;

}

}

public class LinkedList

{

Student First { get; set; }

public void Insert(Student p_Student)

{

if (First == null)

First = p_Student;

else

{

Student current = First;

while (current.Next != null)

{

current = current.Next;

}

current.Next = p_Student;

}

}

public Student Delete(int p_Position)

{

Student current = First, previous = First;

if (p_Position > 0 && First != null)

{

int count = 1;

while (current.Next != null)

{

if (p_Position == count)

break;

previous = current;

current = current.Next;

count++;

}

previous.Next = current.Next;

if (First.Next == null && p_Position == 1)

First = null;

}

return current;

}

public string SearchByLastName(string p_LName)

{

Student current = First;

string names = string.Empty;

if (current != null)

{

while (current.Next != null)

{

if (current.LName.Equals(p_LName))

names = names + ” Student: ” + current.FName + ” ” + current.LName;

current = current.Next;

}

if (current.LName.Equals(p_LName))

names = “Student: ” + current.FName + ” ” + current.LName;

}

return names;

}

public int Length()

{

Student current = First;

int count = 0;

if (current != null)

{

count = 1;

while (current.Next != null)

{

count++;

current = current.Next;

}

}

return count;

}

public string Display()

{

return Display(0, 0);

}

//p_Start =0, p_End =0 displays whole list, Method Overloading

public string Display(int p_Start, int p_End)

{

int length = Length();

if (First == null)

return “Database Is Empty.”;

else if (p_Start < 0 || p_End < 0 || p_Start > length || p_End > length)

return “Invalid Range.”;

else

{

string studentsInfo = string.Empty;

if (First != null && p_Start >= 0 && p_End >= 0)

{

int count = 1;

Student current = First;

while (current.Next != null)

{

count++;

if (count – 1 >= p_Start &&

(p_End == 0 || (p_End != 0 && count <= p_End)))

studentsInfo = studentsInfo + current.Display();

current = current.Next;

}

studentsInfo = studentsInfo + current.Display();

}

return studentsInfo;

}

}

public double CourseAvg(string p_CourseCode)

{

double totGrade = 0;

int enrolledStudentsCount = 0;

if (First != null)

{

Student current = First;

while (current.Next != null)

{

if (current.CourseCode.Trim().ToUpper().Equals(p_CourseCode.ToUpper().Trim()))

{

enrolledStudentsCount++;

totGrade = totGrade + current.Grade;

}

current = current.Next;

}

if (current.CourseCode.Trim().ToUpper().Equals(p_CourseCode.ToUpper().Trim()))

{

enrolledStudentsCount++;

totGrade = totGrade + current.Grade;

}

}

return totGrade / (enrolledStudentsCount == 0 ? 1 : enrolledStudentsCount);

}

}

class Program

{

static void Main(string[] args)

{

LinkedList students = new LinkedList();

Student st1 = new Student { FName = “Ram”, LName = “One”, CourseCode = “DS”, Grade = 3.2 };

students.Insert(st1);

students.Insert(new Student { FName = “Ram”, LName = “Two”, CourseCode = “DS”, Grade = 3.3 });

Console.WriteLine(students.Display());

Console.ReadLine();

while (true)

{

Console.WriteLine(“Press 1 to insert a new record\n\r”

+ “Press 2 to delete a record\n\r”

+ “Press 3 to search the database (by last name)\n\r”

+ “Press 4 to print a range in the database\n\r”

+ “Press 5 to find the class average for a course\n\r”

+ “Press 9 to quit\n\r\n\rAnd Press Enter”

);

string choice = Console.ReadLine();

if (choice.Equals(“1”))

{

Console.WriteLine(“Enter Student’s First Name & Press Enter:\n\r”);

string fName = Console.ReadLine();

Console.WriteLine(“Enter Student’s Last Name & Press Enter:\n\r”);

string lName = Console.ReadLine();

Console.WriteLine(“Enter Student’s Course Code & Press Enter:\n\r”);

string courseCode = Console.ReadLine();

Console.WriteLine(“Enter Student’s Grade & Press Enter:\n\r”);

double grade = 0;

while (true)

{

try

{

grade = double.Parse(Console.ReadLine());

break;

}

catch

{

Console.WriteLine(“Enter valid Grade(1 to 4) & Press Enter\n\r”);

}

}

students.Insert(new Student { FName = fName, LName = lName, CourseCode = courseCode, Grade = grade });

Console.WriteLine(“Student details has been inserted into the database.\n\r”);

}

else if (choice.Equals(“2”))

{

Console.WriteLine(“Enter Delete Position & Press Enter:\n\r”);

int position = 0;

while (true)

{

try

{

position = Int32.Parse(Console.ReadLine());

break;

}

catch

{

Console.WriteLine(“Enter Valid Delete Postion & Press Enter\n\r”);

}

}

if (students.Delete(position) != null)

Console.WriteLine(“Student record from the database has been deleted from the specified position.\n\r”);

else

Console.WriteLine(“Database Is Empty.\n\r”);

}

else if (choice.Equals(“3”))

{

Console.WriteLine(“Enter Last Name To Search & Press Enter:\n\r”);

string lName = Console.ReadLine();

Console.WriteLine(“Serach Result:\n\r” + students.SearchByLastName(lName));

}

else if (choice.Equals(“4”))

{

Console.WriteLine(“Enter Start Position & Press Enter:\n\r”);

int startPosition = 0;

while (true)

{

try

{

startPosition = Int32.Parse(Console.ReadLine());

break;

}

catch

{

Console.WriteLine(“Enter Valid Start Postion & Press Enter\n\r”);

}

}

Console.WriteLine(“Enter End Position & Press Enter:\n\r”);

int endPosition = 0;

while (true)

{

try

{

endPosition = Int32.Parse(Console.ReadLine());

break;

}

catch

{

Console.WriteLine(“Enter Valid End Postion & Press Enter\n\r”);

}

}

Console.WriteLine(“Student Details For The Specified Range:\n\r” + students.Display(startPosition, endPosition));

}

else if (choice.Equals(“5”))

{

Console.WriteLine(“Enter Course Code & Press Enter:\n\r”);

string courseCode = Console.ReadLine();

Console.WriteLine(“Average Marks Of The Course: ” + students.CourseAvg(courseCode) + “\n\r”);

}

else if (choice.Equals(“9”))

break;

}

}

}

}

For more info –

Part1/Part2 Series –

http://www.youtube.com/watch?v=SbVxGOye5eE

http://www.youtube.com/watch?v=tTo72qNB7n4&feature=watch_response

Doubly Linked List –

http://www.codeproject.com/KB/recipes/doubly-linkedlist.aspx

Using C# In-built LinkedList DataStructure –

http://www.dotnetperls.com/linkedlist

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http://blogs.msdn.com/b/tmarq/archive/2010/04/01/asp-net-4-0-enables-routing-of-extensionless-urls-without-impacting-static-requests.aspx

http://www.sqlservercentral.com/articles/SQL+Server+Agent/67726/

Key Take Aways –

select * from dbo.sysjobs — All the jobs in the Server instance
select * from dbo.sysjobsteps — All the steps for the jobs
select * from dbo.Sysjobactivity — The current status of each job. This is particularly useful for seeing if a job is running, or when it last ran.
select * from dbo.sysjobhistory — The history of each job when it ran, including all job steps, until truncated (this is what you see in the Log File viewer)
select * from dbo.sysjobstepslogs — The job step log for certain jobs.
— View History on SQL Agent Job show max 1KB error message from Message column of sysjobhistory table but the sysjobstepslogs table can have 2Bn characters of log info from log column
— run_status = 0 means job step is failed

*SP code to get error message for a job step

ReSharper 2.x / IDEA scheme

http://www.jetbrains.com/resharper/docs/ReSharper60DefaultKeymap_IDEA_scheme.pdf

http://www.jetbrains.com/resharper/docs/ReSharper45DefaultKeymap2.pdf

Visual Studio scheme

http://www.jetbrains.com/resharper/docs/ReSharper60DefaultKeymap_VS_scheme.pdf

http://www.jetbrains.com/resharper/docs/ReSharper45DefaultKeymap.pdf

Mapping  between ReSharper 2.x / IDEA scheme Vs Visual Studio scheme

http://www.jetbrains.com/resharper/webhelp50/Reference__Keyboard_Shortcuts.html