DISE - Database Concepts
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Transcript of DISE - Database Concepts
Diploma in Software Engineering
Module V: Windows Based Application Development in C#
Rasan SamarasingheESOFT Computer Studies (pvt) Ltd.No 68/1, Main Street, Pallegama, Embilipitiya.
Contents1. Introduction to .NET Framework2. .NET Framework Platform Architecture3. Microsoft Visual Studio4. C# Language5. C#, VS and .NET Framework Versions6. Your First C# Application7. Printing Statements8. Comments in C#9. Common Type System10. Value Types and Reference Type11. Variables Declaration in C#12. Type Conversion13. Arithmetic Operators14. Assignment Operators15. Comparison Operators16. Logical Operators17. If Statement18. If… Else Statement19. If… Else if… Else Statement20. Nested If Statement21. Switch Statement22. While Loop23. Do While Loop
23. For Loop24. Arrays25. Accessing Arrays using foreach Loop26. Two Dimensional Arrays27. Classes and Objects in C#28. Inheritance in C#29. Partial Classes30. Namespaces31. Windows Forms Applications32. Using Buttons, Labels and Text Boxes33. Displaying Message Boxes34. Error Handling with Try… Catch… finally…35. Using Radio Buttons36. Using Check Boxes37. Using List Boxes38. Creating Menus39. Creating ToolStrips40. MDI Forms41. Database Application in C#42. Creating a Simple Database Application43. SQL Insert / Update / Retrieving / Delete44. SQL Command Execute Methods45. Data Sets
Introduction to .NET Framework
• The .NET Framework is a software framework developed by Microsoft that runs primarily on Microsoft Windows.
• It includes a large library and provides language interoperability across several programming languages.
• Programs written for .NET Framework execute in a software environment known as CLR.
• .NET Framework is intended to be used by most new applications created for the Windows platform.
.NET Framework Platform Architecture
Microsoft Visual Studio
• Microsoft Visual Studio is an integrated development environment (IDE) from Microsoft…
• To develop Windows Forms or WPF applications, web sites, web applications, and web services…
• For Microsoft Windows, Windows Mobile, Windows CE, .NET Framework and Microsoft Silverlight.
C# Language
C# is a general purpose, object oriented programming language developed by Microsoft within its .NET initiative led by Anders Hejlsberg.
C# Language Features
• Boolean Conditions • Automatic Garbage Collection • Standard Library • Assembly Versioning • Properties and Events • Delegates and Events Management • Easy-to-use Generics • Indexers • Conditional Compilation • Simple Multithreading • LINQ and Lambda Expressions • Integration with Windows
C#, VS and .NET Framework Versions
C# Version Visual Studio Version .NET Framework VersionC# 1.0 Visual Studio .NET 2002 .NET Framework 1.0
C# 1.2 Visual Studio .NET 2003 .NET Framework 1.1
C# 2.0 Visual Studio 2005 .NET Framework 2.0
C# 3.0 Visual Studio 2008Visual Studio 2010
.NET Framework 2.0
.NET Framework 3.0
.NET Framework 3.5
C# 4.0 Visual Studio 2010 .NET Framework 4
C# 5.0 Visual Studio 2012Visual Studio 2013 .NET Framework 4.5
Your First C# Application
using System;
namespace myspace{
class FirstApp{ static void Main() { Console.WriteLine(“Hello World!”); }}
}
Printing Statements
Console.Write(“Hello World!”); //prints a text
Console.WriteLine(“Hello World!”); //printing end up with a new line
Console.Write(“Hello \nWorld!”); //line breaks
Console.Write(“Hello {0}”, “Esoft”); //variable displaying
Comments in C#
Single line comments
// this is a single line comment
Multiline comments
/* this is a multilinecomment*/
Common Type System
Value Types and Reference TypePredefined Value Types
sbyte -128 to 127 8 bitsbyte 0 to 255 8 bitsshort -32,768 to 32,767 16 bitsushort 0 to 65,535 16 bitsint -2,147,483,648 to 2,147,483,647 32 bitsuint 0 to 4,294,967,295 32 bitslong -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 64 bitsulong 0 to 18,446,744,073,709,551,615 64 bitschar 16 bit Unicode character 16 bitsfloat -3.4 x 1038 to + 3.4 x 1038 32 bitsdouble (+/-)5.0 x 10-324 to (+/-) 1.7 x 10308 64 bitsdecimal (-7.9 x 1028 to 7.9 x 1028) / 100 to 28 128 bitsbool Holds true or false 1 bit
Predefined Reference Typesstring Represents a string of Unicode characters 20+ bitsobject Represents a general purpose type 8+ bits
Variable Declaration in C#
Variable declarationtype variable_list;
Variable declaration and initializationtype variable_name = value;
Variables Declaration in C#
int a, b, c; // declares three ints, a, b, and c.
int d = 3, e, f = 5; // declares three more ints, initializing d and f.
bool z = 5>2; // declares and initializes z.
double pi = 3.14159; // declares an approximation of pi.
char x = 'x'; // the variable x has the value 'x'.
Type Conversion
• Implicit Conversion – No special syntax is required because the
conversion is type safe and no data will be lost.
• Explicit Conversion– Require a cast operator, and information might be
lost in the conversion.
• Conversions with helper classes– To convert between non-compatible types.
Implicit Conversion
int x = 123;double y = x;
Explicit Conversion
double y = 123.5;int x = (int)y;
Conversions with helper classes
String x = "123";int y = Int.Parse(x);int z = Convert.ToInt32(x);
Arithmetic Operators
Operator Description Example+ Addition X + Y will give 60
- Subtraction X - Y will give -20
* Multiplication X * Y will give 800
/ Division Y / X will give 2
% Modulus Y % X will give 0
++ Increment Y++ gives 41
-- Decrement Y-- gives 39
X = 20, Y = 40
Assignment Operators
Operator Example
= Z = X + Y will assign value of X + Y into Z
+= Z += X is equivalent to Z = Z + X
-= Z -= X is equivalent to Z = Z - X
*= Z *= X is equivalent to Z = Z * X
/= Z /= X is equivalent to Z = Z / X
%= Z %= X is equivalent to Z = Z % X
Comparison Operators
Operator Example
== (X == Y) is false.
!= (X != Y) is true.
> (X > Y) is false.
< (X < Y) is true.
>= (X >= Y) is false.
<= (X <= Y) is true.
X = 50, Y = 70
Logical Operators
Operator Name Example
&& AND (X && Y) is False
|| OR (X || Y) is True
! NOT !(X && Y) is True
X = True, Y = False
If Statement
if(Boolean_expression){ // Statements will execute if the Boolean
expression is true}
Boolean Expression
Statements
True
False
If… Else Statementif(Boolean_expression){ // Executes when the Boolean expression is true}Else{ // Executes when the Boolean
expression is false}
Boolean Expression
Statements
True
False
Statements
If… Else if… Else Statementif(Boolean_expression 1){ // Executes when the Boolean expression 1 is true}else if(Boolean_expression 2){ // Executes when the Boolean expression 2 is true}else if(Boolean_expression 3){ // Executes when the Boolean expression 3 is true}else { // Executes when the none of the above condition is true.}
If… Else if… Else Statement
Boolean expression 1
False
Statements
Boolean expression 2
Boolean expression 3
Statements
Statements
False
False
Statements
True
True
True
Nested If Statement
if(Boolean_expression 1){ // Executes when the Boolean expression 1 is true if(Boolean_expression 2) { // Executes when the Boolean expression 2 is true }}
Boolean Expression 1
True
False
StatementsBoolean Expression 2
True
False
Switch Statement
switch (value) { case constant: // statements break; case constant: // statements break; default: // statements break; }
While Loop
while(Boolean_expression){ // Statements}
Boolean Expression
Statements
True
False
Do While Loop
do{ // Statements}while(Boolean_expression);
Boolean Expression
Statements
True
False
For Loop
for(initialization; Boolean_expression; update){ // Statements}
Boolean Expression
Statements
True
False
Update
Initialization
Arrays
10 30 20 50 15 35
0 1 2 3 4 5
Size = 6
Element Index No
An Array can hold many values in a same data type under a single name
A single dimensional array
Building a Single Dimensional Array
// creating an arrayDataType[] ArrayName = new DataType[size];
// assigning valuesArrayName[index] = value;ArrayName[index] = value;……..
Building a Single Dimensional Array
char[] letters = new char[4];
letters[0] = ‘O’;letters[1] = ‘P’;letters[2] = ‘Q’;letters[3] = ‘R’;
0 1 2 3
O P Q R
0 1 2 3
letters
letters
Values in an Array can access by referring index number
Building a Single Dimensional Array
// creating an array with array initializerDataType[] ArrayName = {element 1, element 2,
element 3, … element n};
int[] marks = {10, 20, 30, 40, 50}; 10 20 30 40
0 1 2 3
intArr
50
4
Accessing Arrays using foreach Loop
// creating an Arrayint[] marks = {10, 29, 30, 40, 50, 70};
// accessing array elementsforeach(int n in marks){System.Console.WriteLine(n);}
Two Dimensional Arrays
5 10 15
25 50 75
0 1 2
0
1
int[,] myMatrix = new int[2,3];
myMatrix[0,0] = 5;myMatrix[0,1] = 10;myMatrix[0,2] = 15;myMatrix[1,0] = 25;myMatrix[1,1] = 50;myMatrix[1,2] = 75;
Rows Columns
Column Index
Row Index
Two Dimensional Arrays
Using array initializer…
int[,] myMatrix = new int[2,3] {{5,10,15},{25,50,75}};
int[,] myMatrix = {{5,10,15},{25,50,75}};
Or
Classes and Objects in C#
Method
Student
nameage
Register()
class Student{
public String name;public int age;
public Student(){}
public void Register(){Console.WriteLine(“Registered!”);}
}
Attributes
Constructor
C# Objects
Student st = new Student(); // creating an object // assigning values to Attributesst.name = “Roshan”; st.age = 20;
// calling methodst.Register();
Inheritance in C#class Animal{//attributes and methods}
class Lion : Animal{//attributes and methods}
class Cat : Animal{//attributes and methods}
Animal
Lion Cat
Partial Classespartial class Student{public int age;}
partial class Student{public String name;}
partial class Student{public String address;
public void Register(){Console.Write("Student Registered");}}
Partials of the same class
Namespaces
• Namespace is an organization construct.
• It’s a group of collected types.
• It’s helping to understand how the code base is arranged.
• Namespaces are not essential for C# programs.
namespace esoft{
class ditec{
}
class dise{
}
}
Importing Namespaces
Importing Namespace by using “using” directiveusing System.Linq;
Importing Namespace with alias directiveusing ns = System.Linq;
Direct accessing NamespacesSystem.Console.WriteLine(“hello”);
Windows Forms Applications
• A Windows Forms application is an event-driven application supported by Microsoft's .NET Framework.
• This model provides object-oriented, extensible set of classes that enable you to develop rich Windows applications.
Using Button, Labels and Text Boxes
private void button1_Click(object sender, EventArgs e){ label2.Text = "Welcome " + textBox1.Text;}
Displaying Message Boxes
MessageBox.Show("Hello World","MessageBox Demo",MessageBoxButtons.YesNo,MessageBoxIcon.Information);
MessageBox.Show("Hello World“);
Error Handling with Try… Catch… finally…
try{//Protected code }catch (Exception ex){//Catch block}finally{//The finally block always executes}
Using Radio Buttons
private void button1_Click(object sender, EventArgs e){ if (radioButton1.Checked) { MessageBox.Show("You have chosen Black"); } else { MessageBox.Show("You have chosen White"); } }
Using Check Boxes
private void button1_Click(object sender, EventArgs e){ if (checkBox1.Checked) { MessageBox.Show("You have accepted Terms of Agreement"); } else { MessageBox.Show("You haven't accepted Terms of Agreement"); } }
Using List BoxesStatements for each button click events
listBox1.Items.Add(textBox1.Text);
listBox1.Items.AddRange(new String[] { “America", “Japan", “India" });
listBox1.Items.Insert(0, textBox1.Text);
listBox1.Items.Remove(listBox1.SelectedItem);
listBox1.Items.RemoveAt(int.Parse(textBox1.Text));
listBox1.Items.Clear();
listBox1.Sorted = true;
Creating Menus
private void newToolStripMenuItem_Click(object sender, EventArgs e){ MessageBox.Show("You have clicked New Menu item!");}
Creating ToolStrips
private void newToolStripButton_Click(object sender, EventArgs e){ MessageBox.Show("You have clicked newToolStripButton!");}
MDI Forms
private void document1ToolStripMenuItem_Click(object sender, EventArgs e){ Document_One form1 = new Document_One(); form1.MdiParent = this; form1.Show();}
Database Application in C#
Application DataBase
Insert, Update, Retrieving and Delete Processes
Creating a Simple Database Application
Creating a simple database application involved with following steps.
1. Import the namespaces2. Creating a SQL Connection3. Open SQL Connection4. Create a SQL Command5. Execute the SQL Command6. Extract data from SQL Data Reader7. Clean up the environment
Creating a Simple Database Applicationusing System;using System.Data.SqlClient;
class Program{static void Main(string[] args) { SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS; Initial Catalog=esoftdb; Integrated Security=yes"); con.Open(); SqlCommand cmd = new SqlCommand("SELECT * FROM tblStudent", con); SqlDataReader rd = cmd.ExecuteReader(); while (rd.Read()) { Console.Write(rd["id"].ToString() + " "); Console.Write(rd["name"].ToString() + " "); Console.WriteLine(rd["address"].ToString()); } rd.Close(); con.Close(); Console.ReadLine();}}
1
2
345
6
7
SQL Insert / Update / Retrieving / Delete
Inserting Data into Database
SqlCommand cmd = new SqlCommand(“INSERT tblStudent VALUES(1, ‘Roshan’, ‘Colombo’)", con);
Updating Data in Database
SqlCommand cmd = new SqlCommand(“UPDATE tblStudent SET address=‘kandy’ WHERE id=1", con);
Retrieving Data from Database
SqlCommand cmd = new SqlCommand("SELECT * FROM tblStudent", con);
Deleting Data in Database
SqlCommand cmd = new SqlCommand(“DELETE FROM tblStudent WHERE id=1", con);
SQL Command Execute Methods
• ExecuteNonQuery() : Executes a Transact-SQL statement against the connection and returns the number of rows affected.
• ExecuteReader() : Sends the CommandText to the Connection and builds a SqlDataReader.
• ExecuteScalar() : Executes the query, and returns the first column of the first row in the result set returned by the query.
int n = cmd.ExecuteNonQuery();
SqlDataReader rd = cmd.ExecuteReader();
String name= cmd.ExecuteScalar();
Data Sets
Represents an in-memory cache of data.
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS; Initial Catalog=esoftdb; Integrated Security=yes");SqlCommand cmd = new SqlCommand("SELECT * FROM tblStudent", con);SqlDataAdapter da = new SqlDataAdapter(cmd);DataSet ds = new DataSet();da.Fill(ds, “tblStudent”);
The End
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