Private typeds As New DataSet Dim mycon As New OleDbConnection Dim mydata As New OleDbDataAdapter

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load mycon.ConnectionString = "provider=microsoft.jet.oledb.4.0;data source=db1.mdb" mydata = New OleDbDataAdapter("select * from xmmc", mycon) mycon.Open() mydata.Fill(typeds) DataGrid1.DataSource = typeds.Tables(0) mycon.Close() End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click mydata = New OleDbDataAdapter("select * from xmmc", mycon) mydata.Update(typeds) End Sub 我修改DataGrid1，内容，按button2更新，提示需要有效的updatecommand？是怎么回事？数据库有主键，我刚学，谢谢大家！