System.Data Namespace

Classes

• DataSet

  Represents an in-memory cache of data. It can hold multiple tables of data and relationships between them.

• DataTable

  Represents a table of data in memory.

• DataRow

  Represents a row of data within a DataTable.

• DataColumn

  Represents a column in a DataTable.

• DataView

  Provides a way to sort, filter, and search data in a DataTable.

• IDbConnection

  Represents a connection to a data source.

• IDbCommand

  Represents a Transact-SQL statement or stored procedure to execute against a data source.

• IDataReader

  Provides a way to read a forward-only stream of rows from a data source.

Enums

• CommandBehavior

  Specifies additional options for executing a command or query.

• ConnectionState

  Indicates the state of a connection to a data source.

• MissingMappingAction

  Specifies how a source table or column is mapped to a destination table or column when no explicit mapping is defined.

Common Usage Example

using System.Data;

// Create a DataSet
var dataSet = new DataSet("MySampleDataSet");

// Create a DataTable
var dataTable = new DataTable("Customers");

// Add columns to the DataTable
dataTable.Columns.Add("CustomerID", typeof(int));
dataTable.Columns.Add("Name", typeof(string));
dataTable.Columns.Add("City", typeof(string));

// Add rows to the DataTable
var row1 = dataTable.NewRow();
row1["CustomerID"] = 1;
row1["Name"] = "Alice Smith";
row1["City"] = "New York";
dataTable.Rows.Add(row1);

var row2 = dataTable.NewRow();
row2["CustomerID"] = 2;
row2["Name"] = "Bob Johnson";
row2["City"] = "London";
dataTable.Rows.Add(row2);

// Add the DataTable to the DataSet
dataSet.Tables.Add(dataTable);

// Accessing data
foreach (DataRow row in dataSet.Tables["Customers"].Rows)
{
    var id = row["CustomerID"];
    var name = row["Name"];
    var city = row["City"];
    // Console.WriteLine($"ID: {id}, Name: {name}, City: {city}");
}

// You would typically use DbConnection and DbCommand to populate the DataSet from a database.
// Example with SqlDataReader (conceptually):
// using (var connection = new SqlConnection("your_connection_string")) {
//     connection.Open();
//     using (var command = new SqlCommand("SELECT * FROM Customers", connection)) {
//         using (var reader = command.ExecuteReader()) {
//             dataTable.Load(reader);
//         }
//     }
// }
                

Explore the members of the System.Data namespace to understand how to effectively manage and manipulate data within your .NET applications.