Connecting to a database in ASP.NET Web Pages allows you to store, retrieve, and manipulate data dynamically. This can be done using various data access technologies, but one of the most common methods is using ADO.NET with SQL Server.

Prerequisites

• Ensure you have a SQL Server database set up.
• Have the connection string ready, which includes the server name, database name, and authentication details.

Step-by-Step Guide to Connect to a Database

1. Define the Connection String: The connection string is used to establish a connection to the database. You can define it in your web page or in the Web.config file.
2. Use ADO.NET to Connect and Query the Database: You can use ADO.NET classes such as SqlConnection, SqlCommand, and SqlDataReader to interact with the database.

Sample Code to Connect to a Database

Below is an example of how to connect to a SQL Server database and retrieve data using ADO.NET in an ASP.NET Web Page.

Step 1: Define the Connection String

        
            @{
                var connectionString = "Server=your_server_name;Database=your_database_name;User  Id=your_username;Password=your_password;";
            }
            

Step 2: Connect to the Database and Retrieve Data

        
            @{
                using System.Data.SqlClient;

                // Define the connection string
                var connectionString = "Server=your_server_name;Database=your_database_name;User  Id=your_username;Password=your_password;";

                // Create a connection to the database
                using (var connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    // Define the SQL query
                    var query = "SELECT * FROM YourTableName";

                    // Create a command to execute the query
                    using (var command = new SqlCommand(query, connection))
                    {
                        // Execute the command and read the data
                        using (var reader = command.ExecuteReader())
                        {
                            while (reader.Read())
                            {
                                <p>@reader["ColumnName"]</p>
                            }
                        }
                    }
                }
            }
            

Explanation of the Code

• Connection String: This string contains the necessary information to connect to the database, including the server name, database name, and credentials.
• SqlConnection: This class is used to establish a connection to the database.
• SqlCommand: This class is used to execute SQL queries against the database.
• SqlDataReader: This class is used to read the data returned by the SQL query in a forward-only manner.

Conclusion

Connecting to a database in ASP.NET Web Pages is a straightforward process using ADO.NET. By defining a connection string and using the appropriate classes, you can easily retrieve and manipulate data from your database. This allows you to create dynamic web applications that can interact with data effectively.