COP2360 – C# Programming

Chapter 12-14ish – April 1

Announcements

 – – Assignment 4 is due April 3 by midnight You can either upload the assignment as specified in the FTP document or email it to me at  [email protected]

DO NOT MAIL IT TO MY PBSC Account  It will just be deleted!!

Tonight

 Test Review  Exception Handling  Beginning Database Access  Remedial Web Forms (Second half of the class.)

Exception Handling

 Try…Catch…Finally  Code that may create a problem is placed in the try block  Code to deal with the problem (the exception handler) is placed in catch blocks – catch clause  Code to be executed whether an exception is thrown or not is placed in the finally block

Try…Catch…Finally

 Generic catch clause – Omit argument list with the catch – Any exception thrown is handled by executing code within that catch block   Control is never returned into the try block after an exception is thrown Using a try … catch block can keep the program from terminating abnormally

Example Code

 No Exception  Generic Exception  Generic Exception with Method  Specific Exception  Make My Own Exception

Introduction to Databases

 As data needs increase, text files become less viable options  Databases store information in records, fields, and tables  Database - collection of records stored in a computer in a systematic way, so that a computer program can consult it to answer questions

Introduction to Databases

 Database management system (DBMS): computer programs used to manage and query databases  Example DBMSs include SQL server, Oracle, and Access – Many DBMSs store data in tabular format  Data in tables are related through common data field keys

Data Providers (

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)

    Microsoft SQL Server – Applications using SQL Server 7.0 or later Oracle – Applications using Oracle data sources Object Linking and Embedding Database (OLE DB) – Applications that use Microsoft Access databases Open Database Connectivity (ODBC) – Applications supported by earlier versions of Visual Studio C# Programming: From Problem Analysis to Program Design 9

Data Providers (

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)

Table 14-3

Core classes that make up ADO.NET data providers C# Programming: From Problem Analysis to Program Design 10

Connecting to the Database (Microsoft SQL Server)

  Add using directive using System.Data.OleDb; Instantiate an object of connection class – Send connection string that includes the actual database provider and the data source (name of the database) string sConnection; sConnection = "Provider=sqloledb;Data Source=pbsc.c1a7eggjev8o.us-east 1.rds.amazonaws.com;Initial Catalog=REGISTRATION;Persist Security Info=True;User ID=cop2360;Password=GoPanthers"; OleDbConnection dbConn; dbConn = new OleDbConnection(sConnection); dbConn.Open(); 11

Our Example Database

 Is Located in the Amazon Cloud  Provider=sqloledb;Data Source=pbsc.c1a7eggjev8o.us-east 1.rds.amazonaws.com;Initial Catalog=REGISTRATION;Persist Security Info=True;User ID=cop2360;Password=GoPanthers  Is a representation of a College Transcript System

The Registration Database

A Basic Select Clause

 Let’s Use the Server Explorer in VS2012 SELECT field-names FROM table-name(s) WHERE condition clause

Let’s Play With The Data

Let’s Access The Data Through a Program