Question

我有一个DataGridView绑定到BindingSource对象的表单，该对象连接到使用Autonumber作为ID字段的Access数据库。

当编辑，删除或创建记录时，我运行DataAdapter的更新方法，该方法运行良好。但是新记录不会显示其ID，并且尝试删除新记录会导致DBConCurrencyException。

有没有办法告诉BindingSource，Databable或Dataset刷新/重新加载记录？显示新记录的自动编号ID的最佳方法是什么？

（警告，我知道这写不好，代码很抽象。）

Private conString As String = "Provider=Microsoft.ACE.OLEDB.12.0; " +
                            "Data Source=C:\data.accdb"
Private conn As OleDbConnection
Private WithEvents da As OleDbDataAdapter
Private ds As DataSet
Private builder As OleDbCommandBuilder
Private WithEvents bs As BindingSource

Private Sub AccessDataGridView_Load(sender As Object, e As EventArgs) Handles Me.Load
    dgv1.AutoGenerateColumns = True
    Call GetData("SELECT * FROM lots")
    dgv1.DataSource = bs
    dgv1.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCells)
End Sub

Private Function GetData(sSQL As String)
    If conn Is Nothing Then
        conn = New OleDbConnection
        conn.ConnectionString = conString
        conn.Open()
    End If
    da = New OleDbDataAdapter(sSQL, conn)
    builder = New OleDbCommandBuilder(da)
    ds = New DataSet
    da.Fill(ds)
    bs = New BindingSource
    bs.DataSource = ds.Tables(0)
End Function

Private Sub bs_CurrentItemChanged(sender As Object, e As EventArgs) Handles bs.CurrentItemChanged
    If ds.HasChanges() = True Then
        da.Update(CType(bs.DataSource, DataTable))
    End If
End Sub

Private Sub bs_ListChanged(sender As Object, e As System.ComponentModel.ListChangedEventArgs) Handles bs.ListChanged
    If ds.HasChanges() = True Then
        da.Update(CType(bs.DataSource, DataTable))
    End If
End Sub

Private Sub da_RowUpdated(sender As Object, e As OleDbRowUpdatedEventArgs) Handles da.RowUpdated
    If e.Status = UpdateStatus.Continue _
          AndAlso e.StatementType = StatementType.Insert Then
        Dim cmdGetIdentity As OleDbCommand
        cmdGetIdentity = New OleDbCommand()
        cmdGetIdentity.CommandText = "SELECT @@IDENTITY"
        cmdGetIdentity.Connection = conn
        e.Row("lotid") = Int32.Parse(cmdGetIdentity.ExecuteScalar().ToString())
        e.Row.AcceptChanges()
        'This appears to work with no problem, but the DataGridView
        'still doesn't show the new ID
        'EDIT
        dgv1.Refresh() 'This fixed the problem mentioned directly above
    End If
End Sub

Answer 1

使用SqlClient时自动生成的ID传播回DataTable的方法是在InsertCommand的CommandText中包含SELECT语句。 Jet和ACE OLE DB提供程序不支持每个命令多个语句，因此这不是一个选项。我已经在另一个网站上专门为Access编写了一些示例代码但是现在它已经关闭，所以我无法给你链接。这是另一个例子：

http://support.microsoft.com/kb/816112/en-gb

该代码是C＃但原理完全相同：处理数据适配器的RowUpdated事件，从数据库中获取ID并更新DataRow。

DataGridView与DataTable / BindingSource不显示新的自动编号ID

1 个答案: