Question

我使用下面提到的代码来更新和删除datagridview中的数据。但我无法解决这个问题。删除工作正常但未更新。

Public Sub CustomerUpdateBatch（ByVal dt As DataTable）

    Dim connection As SqlConnection = New SqlConnection(Invoice.GetConnect())
    connection.Open()
    Try

        Dim command As SqlCommand = New SqlCommand("Update_Customer", connection)
        command.CommandType = CommandType.StoredProcedure
        command.Parameters.Add("@C_ID", SqlDbType.Int, 16, "C_ID")
        command.Parameters.Add("@C_Name", SqlDbType.VarChar, 50, "C_Name")
        command.Parameters.Add("@C_Address", SqlDbType.VarChar, 50, "C_Address")
        command.Parameters.Add("@C_Tel", SqlDbType.VarChar, 50, "C_Tel")
        command.Parameters.Add("@C_Fax", SqlDbType.VarChar, 50, "C_Fax")
        command.Parameters.Add("@C_Mobile", SqlDbType.VarChar, 50, "C_Mobile")
        command.Parameters.Add("@C_Email", SqlDbType.VarChar, 50, "C_Email")
        command.Parameters.Add("@C_Tin", SqlDbType.VarChar, 50, "C_Tin")
        command.Parameters.Add("@C_Remarks", SqlDbType.VarChar, 50, "C_Remarks")
        command.CommandType = CommandType.StoredProcedure

        Dim delcommand As SqlCommand = New SqlCommand("Delete_Customer", connection)
        delcommand.CommandType = CommandType.StoredProcedure
        command.Parameters.Add("@C_ID", SqlDbType.Int, 16, "C_ID")

        Dim adapter As SqlDataAdapter = New SqlDataAdapter()
        adapter.UpdateCommand = command
        adapter.DeleteCommand = delcommand
        adapter.DeleteCommand.UpdatedRowSource = UpdateRowSource.None
        adapter.Update(dt)

    Catch ex As Exception
        Console.WriteLine(ex.Message)
        Throw
    Finally
        connection.Close()
    End Try
End Sub

Answer 1

一个可能的问题与使用自动编号索引有关。向表中添加新数据时，不会自动生成或从数据库中获取索引。您没有说出您拥有的数据库，但我将向您展示MySQL和MS SQL的示例。

首先，您需要捕获数据适配器的事件。 “Connection”和“Dataadapter”定义需要在您的函数之外：

    Dim WITHEVENTS adapter As SqlDataAdapter = New SqlDataAdapter()

然后你需要有一个函数来捕获这些事件：

Private Sub myAdapter_RowUpdated(ByVal sender As Object, ByVal e As System.Data.OleDb.OleDbRowUpdatedEventArgs) Handles adapter.RowUpdated
    If (e.StatementType = StatementType.Insert And e.Status = UpdateStatus.Continue) Then
        Dim id As ULong = getIdentity()
        If (id > 0) Then
            e.Row(0) = id
        End If
    End If
End Sub

getIdentiy（）函数需要特定于您的SQL服务器。这个是针对MySQL的：

Public Function getIdentity() As ULong
        Dim newcommand As New MySqlCommand("SELECT LAST_INSERT_ID();", connection)
        Return newcommand.ExecuteScalar()
    End Function

这是MS SQL的一个：

Public Function getIdentity() As ULong
        Dim newcommand As New OleDbCommand("SELECT @@IDENTITY", connection)
        Return newcommand.ExecuteScalar()
 End Function

如何使用vb.net更新datagridview

1 个答案: