C# Database Programming Tutorial346

Introduction

In this tutorial, we will learn how to access and manipulate data in a database using C#. We will cover the basics of database programming, such as connecting to a database, executing queries, and inserting, updating, and deleting data.

Prerequisites
Basic understanding of C#
A database server (e.g., Microsoft SQL Server, MySQL, Oracle)
A database client (e.g., Microsoft SQL Server Management Studio, MySQL Workbench, Oracle SQL Developer)

Step 1: Connect to the Database

The first step is to connect to the database. We can use the namespace to connect to a Microsoft SQL Server database.```csharp
// Connection string
string connectionString = @"Data Source=localhost;Initial Catalog=MyDatabase;Integrated Security=True";
// Create a connection
SqlConnection connection = new SqlConnection(connectionString);
// Open the connection
();
```

For other database servers, we can use the appropriate namespace and connection string.Step 2: Execute a Query

Once we are connected to the database, we can execute a query to retrieve data. We can use the SqlCommand class to execute a query.```csharp
// Create a command
SqlCommand command = new SqlCommand("SELECT * FROM Customers", connection);
// Execute the query
SqlDataReader reader = ();
// Read the results
while (())
{
("{0} {1}", reader["CustomerID"], reader["CustomerName"]);
}
// Close the reader
();
```

The SqlDataReader object provides us with access to the results of the query.Step 3: Insert Data

To insert data into a database, we can use the InsertCommand property of the SqlCommand class.```csharp
// Create a command
SqlCommand command = new SqlCommand("INSERT INTO Customers (CustomerName, Address) VALUES (@CustomerName, @Address)", connection);
// Add parameters
("@CustomerName", "John Doe");
("@Address", "123 Main Street");
// Execute the command
();
```

The ExecuteNonQuery method returns the number of rows affected by the command.Step 4: Update Data

To update data in a database, we can use the UpdateCommand property of the SqlCommand class.```csharp
// Create a command
SqlCommand command = new SqlCommand("UPDATE Customers SET Address = @Address WHERE CustomerID = @CustomerID", connection);
// Add parameters
("@Address", "456 Elm Street");
("@CustomerID", 1);
// Execute the command
();
```

The ExecuteNonQuery method returns the number of rows affected by the command.Step 5: Delete Data

To delete data from a database, we can use the DeleteCommand property of the SqlCommand class.```csharp
// Create a command
SqlCommand command = new SqlCommand("DELETE FROM Customers WHERE CustomerID = @CustomerID", connection);
// Add parameters
("@CustomerID", 1);
// Execute the command
();
```

The ExecuteNonQuery method returns the number of rows affected by the command.Step 6: Close the Connection

Once we are finished with the database, we should always close the connection.```csharp
// Close the connection
();
```

Closing the connection releases the resources used by the connection.Conclusion

In this tutorial, we have learned the basics of database programming in C#. We have covered how to connect to a database, execute queries, and insert, update, and delete data. This knowledge will allow us to develop applications that can interact with databases.

2025-01-11

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