CRUD VB

main.vb

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
    Me.BindGrid()
    Dim checkBoxColumn As DataGridViewCheckBoxColumn = New DataGridViewCheckBoxColumn()
    checkBoxColumn.HeaderText = ""
    checkBoxColumn.Width = 30
    checkBoxColumn.Name = "checkBoxColumn"
    dataGridView1.Columns.Insert(0, checkBoxColumn)
    AddHandler dataGridView1.CellContentClick, AddressOf DataGridView_CellClick
End Sub
 
Private Sub Insert(sender As System.Object, e As System.EventArgs) Handles button1.Click
    Using con As SqlConnection = New SqlConnection(ConnectionString)
        Using cmd As SqlCommand = New SqlCommand("INSERT INTO Customers(Name,Country) VALUES(@Name,@Country)", con)
            cmd.Parameters.AddWithValue("@Name", txtName.Text)
            cmd.Parameters.AddWithValue("@Country", txtCountry.Text)
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using
 
    Me.BindGrid()
    txtId.Clear()
    txtName.Clear()
    txtCountry.Clear()
End Sub
 
Private Sub Update(sender As System.Object, e As System.EventArgs) Handles button2.Click
    Using con As SqlConnection = New SqlConnection(ConnectionString)
        Using cmd As SqlCommand = New SqlCommand("UPDATE Customers SET Name = @Name , Country = @Country WHERE CustomerId = @CustomerId", con)
            cmd.Parameters.AddWithValue("@Name", txtName.Text)
            cmd.Parameters.AddWithValue("@Country", txtCountry.Text)
            cmd.Parameters.AddWithValue("@CustomerId", txtId.Text)
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using
 
    Me.BindGrid()
    txtId.Clear()
    txtName.Clear()
    txtCountry.Clear()
End Sub
 
Private Sub Delete(sender As System.Object, e As System.EventArgs) Handles button3.Click
    Using con As SqlConnection = New SqlConnection(ConnectionString)
        Using cmd As SqlCommand = New SqlCommand("DELETE FROM Customers WHERE CustomerId = @CustomerId", con)
            cmd.Parameters.AddWithValue("@CustomerId", txtId.Text)
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using
 
    Me.BindGrid()
    txtId.Clear()
    txtName.Clear()
    txtCountry.Clear()
End Sub
 
Private Sub BindGrid()
    Using con As SqlConnection = New SqlConnection(ConnectionString)
        Using cmd As SqlCommand = New SqlCommand("SELECT CustomerId, Name, Country FROM Customers", con)
            cmd.CommandType = CommandType.Text
            Using sda As SqlDataAdapter = New SqlDataAdapter(cmd)
                Using dt As DataTable = New DataTable()
                    sda.Fill(dt)
                    dataGridView1.DataSource = dt
                End Using
            End Using
        End Using
    End Using
End Sub
 
Private Sub DataGridView_CellClick(ByVal sender As Object, ByVal e As DataGridViewCellEventArgs)
    If e.RowIndex >= 0 AndAlso e.ColumnIndex = 0 Then
        For Each row As DataGridViewRow In dataGridView1.Rows
            If row.Index = e.RowIndex Then
                row.Cells("checkBoxColumn").Value = Not Convert.ToBoolean(row.Cells("checkBoxColumn").EditedFormattedValue)
                txtId.Text = row.Cells(1).Value.ToString()
                txtName.Text = row.Cells(2).Value.ToString()
                txtCountry.Text = row.Cells(3).Value.ToString()
            Else
                row.Cells("checkBoxColumn").Value = False
            End If
        Next
    End If
End Sub