Explore practical code examples and sample applications that demonstrate how to use OLE DB for data access in your .NET applications. These samples cover various scenarios, from basic connectivity to advanced querying and data manipulation.
Featured Samples
Connecting to a SQL Server Database
A fundamental sample demonstrating how to establish a connection to a SQL Server database using OLE DB providers.
// VB.NET Example
Imports System.Data.OleDb
Public Class DataQuerier
Public Function GetData(connectionString As String, queryString As String) As DataTable
Dim dt As New DataTable()
Using connection As New OleDbConnection(connectionString)
Try
connection.Open()
Dim adapter As New OleDbDataAdapter(queryString, connection)
adapter.Fill(dt)
Return dt
Catch ex As OleDbException
Console.WriteLine($"Error: {ex.Message}")
Return Nothing
End Try
End Using
End Function
End Class
Inserting and Updating Records
Sample code for performing data modification operations like INSERT and UPDATE using OLE DB commands.
// C# Example with Parameters
using System.Data.OleDb;
public class DataModifier
{
public void UpdateRecord(string connectionString, int id, string newName)
{
string query = "UPDATE Customers SET Name = ? WHERE ID = ?";
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
using (OleDbCommand command = new OleDbCommand(query, connection))
{
command.Parameters.AddWithValue("@p1", newName);
command.Parameters.AddWithValue("@p2", id);
try
{
connection.Open();
int rowsAffected = command.ExecuteNonQuery();
Console.WriteLine($"{rowsAffected} row(s) updated.");
}
catch (OleDbException ex)
{
Console.WriteLine($"Error: {ex.Message}");
}
}
}
}
}
Working with Access Databases
Demonstrates OLE DB connectivity and operations specifically for Microsoft Access databases.
' VB.NET Example for Access
Imports System.Data.OleDb
Public Class AccessHandler
Public Function GetAccessData(dbPath As String, tableName As String) As DataTable
Dim connectionString As String = $"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={dbPath};"
Dim query As String = $"SELECT * FROM [{tableName}]"
Dim dt As New DataTable()
Using conn As New OleDbConnection(connectionString)
Try
conn.Open()
Dim adapter As New OleDbDataAdapter(query, conn)
adapter.Fill(dt)
Return dt
Catch ex As Exception
Console.WriteLine($"Error accessing Access DB: {ex.Message}")
Return Nothing
End Try
End Using
End Function
End Class