vb.net 无效操作异常未处理更新需要有效的更新命令

invalid operation exception was unhandled Update requires a valid UpdateCommand

提问by larca

From these codes, I want to edit, add and save data from VB to MS Access permanently. I created dozens of Visual Basic projects but no progress at all.

从这些代码中，我想从 VB 永久编辑、添加和保存数据到 MS Access。我创建了几十个 Visual Basic 项目，但一点进展都没有。

Public Class Form1

    Private Sub ProductDescBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ProductDescBindingNavigatorSaveItem.Click

        Me.Validate()
        Me.ProductDescBindingSource.EndEdit()
        Me.TableAdapterManager.UpdateAll(Me.INVSYSDataSet)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        'TODO: This line of code loads data into the 'INVSYSDataSet.ProductDesc' table. You can move, or remove it, as needed.
        Me.ProductDescTableAdapter.Fill(Me.INVSYSDataSet.ProductDesc)
    End Sub
End Class

The problem is that "invalid operation exception was unhandled" appears, Update requires a valid UpdateCommandfrom code Me.TableAdapterManager.UpdateAll(Me.INVSYSDataSet)

问题是出现“invalid operation exception was unhandled”，Update需要一个valid UpdateCommandfrom codeMe.TableAdapterManager.UpdateAll(Me.INVSYSDataSet)

If you need the DataSource, I can provide code from another VB project.

如果您需要数据源，我可以提供来自另一个 VB 项目的代码。

*updated second code, help for sql please *updated srry bout that

*更新了第二个代码，请帮助sql *更新srry回合

Public Class Add_Products

公共类 Add_Products

Private myConString As String
Private con As OleDb.OleDbConnection = New OleDb.OleDbConnection
Private Dadapter As OleDb.OleDbDataAdapter
Private DSet As DataSet
Private DSet2 As DataSet
Private ConCMD As OleDb.OleDbCommand
Dim strSql As String
Dim inc As Integer
Dim MaxRows As Integer

Private Sub Add_Products_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    myConString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\larca\Documents\Visual Studio 2010\Projects\march16\march16\obj\x86\Debug\INVSYS.mdb"
    con.ConnectionString = myConString
    con.Open()
    Dadapter = New OleDb.OleDbDataAdapter("select * from ProductDesc", con)
    DSet = New DataSet
    Dadapter.Fill(DSet, "ProductDesc")
    DataGridView1.DataSource = DSet.Tables("ProductDesc")

    con.Close()
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Try
        Using con = New OleDb.OleDbConnection(myConString)
            con.Open()
            Dim cmd As OleDb.OleDbCommand
            cmd = New OleDb.OleDbCommand("UPDATE ProductDesc", con)
            Dadapter.UpdateCommand = cmd
            Dadapter.Update(DSet, "ProductDesc")
        End Using
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

End Class

结束班

回答by Tim

The error message is telling you that you have not defined an Update command for the DataAdapter. From DbDataAdapter.Update Method DataSet, String: If INSERT, UPDATE, or DELETE statements have not been specified, the Update method generates an exception.

该错误消息告诉您尚未为 DataAdapter 定义更新命令。从DbDataAdapter.Update 方法数据集，字符串：If INSERT, UPDATE, or DELETE statements have not been specified, the Update method generates an exception.

To resolve this, assign the UpdateCommandan OleDbCommandobject with your update logic, like this:

要解决此问题，请使用更新逻辑分配UpdateCommand一个OleDbCommand对象，如下所示：

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

   Using con = New OleDb.OleDbConnection(myConString)
       con.Open()
       Dim cmd As OleDbCommand
       cmd = New OleDbCommand("<your update SQL goes here>", con)
       DAdapter.UpdateCommand = cmd 
       Dadapter.Update(DSet, "ProductDesc")
   End Using

End Sub

结束子

Simply put your SQL in the OleDbCommandand assign it to the UpdateCommandproperty.

只需将您的 SQL 放入OleDbCommand并将其分配给UpdateCommand属性。

Look at this link for a detailed example (and be sure to use parameterized queries like in the example to avoid SQL Injection attacks): OleDbDataAdapter.UpdateCommand Property

查看此链接以获取详细示例（并确保使用示例中的参数化查询以避免 SQL 注入攻击）：OleDbDataAdapter.UpdateCommand 属性