Introduction to C# and DB programming using ADO

32 Pages·2007·0.15 MB·English

Introduction to C# and DB
programming using ADO.NET
Shahin Shayandeh
October 2007
Outline
(cid:134) .NET Framework
(cid:134) Object Oriented Programming (OOP)
(cid:134) C# basics
(cid:134) Database programming using
ADO.NET
.NET Framework
(cid:134) Development
Languages
(cid:132) C++, C#, J#, Python,
Perl, …
(cid:134) Integrated
Development
Environment (IDEs)
(cid:132) Visual Studio .NET,
Mono Project
(cid:134) Common Language
Infrastructure (CLI)
.NET Framework (Cont’d)
(cid:134) Common Language Infrastructure (CLI)
(cid:132) Microsoft's implementation of the CLI is called the
Common Language Runtime (CLR)
(cid:132) CLR primary components:
(cid:134) Common Type System (CTS)
(cid:132) Type definitions independent of any specific programming
language
(cid:134) Common Language Specification (CLS)
(cid:134) Just-In-Time compiler (JIT) and Intermediate Language
(IL)
(cid:132) Language Independent
(cid:132) Abstraction similar to Java’s Virtual Machine
(cid:134) Virtual Execution System (VES)
(cid:132) Memory management and garbage collection
(cid:132) Exception handling
.NET Framework (Cont’d)
(cid:134) Documentation, examples, tips:
(cid:132) Microsoft Developer Network (MSDN)
(cid:132) Search Engines
(cid:134) Google code search ( )
http://www.google.com/codesearch
(cid:132) Programming websites and forums
(cid:134) Most of the times your question has been
answered before – needs patience and good
search keywords!!
(cid:132) Books, online tutorials, …
OOP: A software construction paradigm
(cid:134) Objects
(cid:132) Abstract concepts, basic entities that describe internal
information (variables) and the means to access it, change its
state, perform actions (functions)
(cid:132) In C# (like Java and most OOP languages) everything is an
object
(cid:134) Classes
(cid:132) Programmer-defined types that model the parts of the system
(objects)
(cid:132) Basically a blueprint
(cid:134) Instances
(cid:132) Building blocks of the code
(cid:132) Allocated in memory sharing the code but not the data
(cid:134) Methods/Variables
(cid:132) Primary mechanisms (code common to all instances of a class)
and data variables
(cid:132) Static parts: belong to a class, accessible and shared by all
instances
OOP (Cont’d)
OOP (Cont’d)
(cid:134) Abstraction
(cid:134) Inheritance
(cid:134) Polymorphism
(cid:134) Encapsulation
(cid:134) Simple example:
…
public class MyNumber {
int val = 20;
public int value() {
return val;
}
public int increase(int how_much) {
val += how_much; //val = val + how much;
return val;
}
}
…
MyNumber m = new MyNumber();
int l = m.value(); // l will be 20
int k = m.increase(12); // k will be 32
C# Basics
(cid:134) Case sensitive
(cid:134) Common data types (primitives):
(cid:132) bool, byte, short/int/long, float/double,
char/string
(cid:134) Conversion
(cid:132) implicitly
(cid:134) float f = 56;
(cid:132) by casting
(cid:134) int i = (int)5.6;
(cid:132) with convert class
(cid:134) int i = System.Convert.ToInt32(3.25d);
(cid:132) provided methods
(cid:134) string s = (5.25).ToString();
Type Casting
(cid:134) Int ⇔ byte array (4 bytes)
(cid:132) byte [] b = BitConverter.GetBytes(integer);
(cid:132) int i = BitConverter.ToInt32(b, 0);
(cid:134) float ⇔ byte array (4 bytes)
(cid:132) byte[] b = BitConverter.GetBytes(float);
(cid:132) float f = BitConverter.ToSingle(b, 0);
(cid:134) String ⇔ byte array
(cid:132) byte[] b = new
ASCIIEncoding().GetBytes(string);
(cid:132) string s = new ASCIIEncoding().GetString(b, 0,
length);