database - 访问 Access 数据库时出现异常

Question

我需要在 Access 表中插入一行。我一直在

对象引用未设置为对象的实例

我的代码是：

Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click

    Dim strconstring As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Daisy\My Documents\Downloads\MusicSales.mdb"
    Dim objcon As OleDb.OleDbConnection
    objcon = New OleDb.OleDbConnection(strconstring)
    Dim objcommand As OleDb.OleDbCommand
    Dim da As New OleDb.OleDbDataAdapter
    Try
        objcon.Open()
        Dim command As String
        command = "insert into Artists(Artist, Company, Sales )" _
             & " values('" & ArtistBox.Text & "', '" _
             & TextBox2.Text & "', " & TextBox3.Text & ")"
        objcommand = New OleDb.OleDbCommand(command, objcon)
        da.InsertCommand.CommandText = command
        da.InsertCommand.ExecuteNonQuery()
    Catch exceptionobject As Exception
        MessageBox.Show(exceptionobject.Message)
    Finally
        objcon.Close()
    End Try
End Sub

Answer 1

您的连接字符串有点乱，所以这可能是导致问题的原因。使用任何一个...

Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Documents and Settings\Daisy\My Documents\Downloads\MusicSales.mdb;

...或者...

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Daisy\My Documents\Downloads\MusicSales.mdb;