Introduction to Database

In everyday life, we deal with a large amount of data such as names, addresses, financial records, medical data, and business transactions.

For example:

• Doctors store patient records
• Businesses manage customers and products
• Banks handle financial transactions

To manage such data efficiently, we use databases.

In the past, data was stored manually using paper files. Today, databases are managed using computer-based Database Management Systems (DBMS), which are faster and more efficient.

Examples of DBMS:

• Microsoft SQL Server
• Oracle
• Microsoft Access

A database system allows you to:

• Store data
• Modify data
• Retrieve data
• Add, edit, and delete records

However, database systems can be complex for non-technical users. Therefore, we create user-friendly applications using Visual Basic.

Visual Basic 2015 uses ADO.NET to interact with databases.

To build database applications, we use the following objects:

• SqlConnection → Connect to database
• DataTable → Store data
• DataAdapter → Transfer data

These belong to:

System.Data
System.Data.SqlClient

To create a database application:

• Create a new project
• Name it (e.g. Database Project)
• Set form title (e.g. Contacts)

Then add references:

• System.Data
• System.Data.SqlClient

You can enable them via:

Project → Properties → References