Developing Visual Basic Applications to Interact with an Access Database Training Session Brian R. Kovar Kansas State University 8 th AIS Educator Annual Meeting June 23, 2006

Concepts Covered in this session Programming –How to link a VB.NET program to a database –Basic SQL –How to bind controls/objects to a dataset –How to create message boxes –IF….Then….Else Selection Statements –Variable Declaration –Object-Oriented Programming –How to create message boxes –Visual Basic programming environment The idea of “program-data independence”. Many other programming and information systems concepts will be covered as well

Programming helps build accounting competencies Programming helps develop and improve problem solving and critical thinking skills. –Increased ability to handle more complex accounting issues and problems (Beard and Smith 2002) AICPA core competency: ability to leverage technology (2004) The lack of programming skills may handicap accountants in working effectively as IS auditors (Calderon, Cheh, Chatham 2002) The Information Systems Audit and Control Association (ISACA) has developed curriculum models stressing the need and importance of computer programming skills.

Tutorials Developed for Classroom Use Creating and Coding an Expert System Using Visual Basic.NET –Published in the Winter 2005 issue of The Review of Business Information Systems. Received a Best Paper Award at the 2004 AIS Educator Conference. Interacting with a Database Using Visual Basic.NET –Presented at the 2005 AIS Educator Conference –Recently accepted for publication in the 2006 C3 project (A Compendium of Classroom Cases and Tools) sponsored by the Information Systems section of the American Accounting Association. Designed to give students an introductory look into how computer programs are created using a computer programming language (VB.NET), as well as give students some basic exposure to the concepts and skills needed to create computer programs. Step-by-step tutorials where students: –Create an expert system (Loan Evaluation ES) –Create programs capable of interacting with an Access database (simple data retrieval and display, as well as SQL queries involving one table and multiple tables)

Interacting with a Database Using Visual Basic.NET VB.NET uses ADO.NET ( ActiveX Data Objects.NET ) to read and write information to a database. –A copy of the records and fields that are needed (called the dataset) is stored in the computer’s memory. –The connection to the database is closed, while the dataset (in memory) is manipulated. –The application (VB.NET program) reconnects to the original database when changes to the dataset need to be saved. Data Adapter (acts as an intermediary between a dataset and the database) The Data Source (Database) DataSet (stored in computer’s memory) VB.NET Application (user interface and program code)

Making a VB.NET application interact with a database 1.Create a connection to a data source (a specific database file and its tables) 2.A Data Adapter must be created to facilitate information transfer back and forth between the data source and the computer program. 3.A Data Set (internal memory data holding area) must be created to hold the data as the application is working with it. Supports the idea of program/data independence Data Adapter (acts as an intermediary between a dataset and the database) The Data Source (Database) DataSet (stored in computer’s memory) VB.NET Application (user interface and program code)

SQL (Structured Query Language) Pronounced as both SQL and sequel A set of commands used to access and manipulate the data stored in a DBMS. Can be used to store, retrieve, update, delete & sort data. SELECT fields FROM table [WHERE condition] [ORDER BY field] SELECT specifies the fields that should be displayed. FROM specifies the table or tables the selected fields are taken from. WHERE is used to limit the records to only those meeting specified criteria. ORDER BY is used to sort the displayed records.

Database Methods (Actions) Dataset = an object representing the data you want to access. –Clear removes all rows in all tables in a dataset. –Fill refreshes/adds data from the source (data source) –Count = the number of items in something (the dataset) –Position = current location in something (the dataset) Binding context is an “object” used to keep track of all datasets. Each dataset can be identified and manipulated while the program is running using its binding context and its parameters (name and names of tables being accessed)

SelectCommand.Parameters(“State”).Value=State is used to modify the filter (subset of records from the original set) established by the WHERE SQL command. –WHERE (State = ?)

Using my Interacting with a Database Using VB.NET tutorial in the classroom Can be used as part of an in-class unit, or it can be used as a stand-alone, self-paced unit. Has been used at both the undergraduate and graduate levels. –Students typically report that the tutorial takes 5-6 hours to complete Must be completed in a computer lab or on a computer that already has Visual Studio/Visual Basic.NET installed. –Software can be obtained for a yearly fee from the Microsoft Software Developer Network Academic Alliance (your college or department may already be a member)

Concepts Covered in this session Programming –How to link a VB.NET program to a database –Basic SQL –How to bind controls/objects to a dataset –How to create message boxes –IF….Then….Else Selection Statements –Variable Declaration –Object-Oriented Programming –How to create message boxes –Visual Basic programming environment The idea of “program-data independence”. Many other programming and information systems concepts were covered as well