If String.IsNullOrWhiteSpace(txtLastName.Text) Then MessageBox.Show("Last Name is required") Return False End If

Using conn As New OleDbConnection(connectionString) Using cmd As New OleDbCommand(query, conn) cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text) cmd.Parameters.AddWithValue("@LastName", txtLastName.Text) cmd.Parameters.AddWithValue("@Email", txtEmail.Text) cmd.Parameters.AddWithValue("@Age", Convert.ToInt32(txtAge.Text)) cmd.Parameters.AddWithValue("@UserID", userID) conn.Open() cmd.ExecuteNonQuery() conn.Close() End Using End Using

Using conn As New OleDbConnection(connectionString) Using cmd As New OleDbCommand(query, conn) ' Add parameters to prevent SQL injection cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text) cmd.Parameters.AddWithValue("@LastName", txtLastName.Text) cmd.Parameters.AddWithValue("@Email", txtEmail.Text) cmd.Parameters.AddWithValue("@Age", Convert.ToInt32(txtAge.Text)) conn.Open() cmd.ExecuteNonQuery() conn.Close() End Using End Using

Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click If dgvUsers.SelectedRows.Count = 0 Then MessageBox.Show("Please select a record to update") Return End If If ValidateInputs() = False Then Exit Sub

' Optional: Display record count lblStatus.Text = $"Loaded dgvUsers.Rows.Count records" End Sub Add this code to the Insert button:

Private Sub LoadData() Dim query As String = "SELECT * FROM Users" Using conn As New OleDbConnection(connectionString) Using adapter As New OleDbDataAdapter(query, conn) Dim table As New DataTable() adapter.Fill(table) dgvUsers.DataSource = table End Using End Using End Sub

Imports System.Data.OleDb Public Class Form1 Dim connectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\VB.NET Projects\Demo\SampleDB.accdb"

MessageBox.Show("Record updated successfully!", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information) LoadData() End Sub Add this to the Delete button:

Private Sub btnDelete_Click(sender As Object, e As EventArgs) Handles btnDelete.Click If dgvUsers.SelectedRows.Count = 0 Then MessageBox.Show("Please select a record to delete") Return End If Dim userID As Integer = Convert.ToInt32(dgvUsers.SelectedRows(0).Cells("UserID").Value)

Using conn As New OleDbConnection(connectionString) Using adapter As New OleDbDataAdapter(query, conn) Dim table As New DataTable() adapter.Fill(table) dgvUsers.DataSource = table End Using End Using

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load LoadData() End Sub

[DataGridView here] Declare a module-level variable for the connection string:

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