有兩個表order(orderid,ordername,totalprice), orderdetail(orderid,productid,productname,price) 已經(jīng)建立一對多 關(guān)聯(lián)(orderid). 用VB.net建立一個窗體, 用于主表和明細表的數(shù)據(jù)錄入及更新. 在窗體上增加兩個sqldataadapter,分別選擇order和orderdetail表, 并生成數(shù)據(jù)集,在DATASET中建立關(guān)聯(lián)(orderid) 主表中:ORDERID,ORDERNAME 綁定在兩個TEXTBOX文本框中,用于接受用戶的輸入,totalprice接受明細表中price 的匯總值. 明細表綁定到一個DATAGRID控件, datasource:dsorder; datamember:order.orderorderdetail建立的關(guān)聯(lián)名稱
問題: 在主表中新增一個記錄,用戶錄入orderid和ordername后,進入明細表的錄入,用戶錄入productid, productname, price后,提示 “明細orderID列不允許空值,要更正該值嗎?” 是什么原因? 用于連接主表的明細orderID如果輸入跟主表一樣的orderID時提示“ForeignKeyconstraint 要求在交叉表中存在子鍵值。要更正該值嗎?”
只有錄入主表中的orderid和ordername后, 先更新主表數(shù)據(jù)源,才可以編輯更新明細表,這是為什么? 請問,有沒有其他更好的方法, 實現(xiàn)主表和明細表的新增記錄同時更新呢? 謝謝關(guān)照! 網(wǎng)友:方宇 回復(fù):http://qsltz@21cn.com http://qsl_tz@hotmail.com
附部分源代碼: Public Class fmOrders Inherits System.Windows.Forms.Form Dim WithEvents dtOrderDetails As New DataTable() Dim BmOrders As BindingManagerBase Dim BmOrderDetails As BindingManagerBase Dim OrderDetailsHasChange As Boolean Dim orderid As DataColumn dim ordername as datacolumn Dim SubTotal As DataColumn Private Sub bnFirst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnFirst.Click BmOrders.Position = 0 End Sub Private Sub bnPrior_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnPrior.Click BmOrders.Position -= 1 End Sub Private Sub bnNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnNext.Click BmOrders.Position += 1 End Sub Private Sub bnLast_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnLast.Click BmOrders.Position = BmOrders.Count - 1 End Sub Private Sub bnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnAdd.Click Try BmOrders.EndCurrentEdit() BmOrders.AddNew() Catch err As System.SystemException MessageBox.Show(err.ToString) End Try End Sub Private Sub bnLoad_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnLoad.Click FillData() End Sub Private Sub bnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnUpdate.Click Dim dsTestOrdersChange As DataSet BmOrderDetails.EndCurrentEdit() BmOrders.EndCurrentEdit() If Not dsTestOrders.HasChanges(DataRowState.Deleted) Then Try daOrders.Update(dsTestOrders, "Orders") daOrderDetails.Update(dsTestOrders, "OrderDetails") dsTestOrders.AcceptChanges() Catch err As System.SystemException dsTestOrders.RejectChanges() MessageBox.Show(err.ToString) Throw End Try Else Try daOrderDetails.Update(dsTestOrders, "OrderDetails") daOrders.Update(dsTestOrders, "Orders") dsTestOrders.AcceptChanges() Catch err As System.SystemException dsTestOrders.RejectChanges() MessageBox.Show(err.ToString) Throw End Try End If End Sub Private Sub fmOrders_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load FillData() dtOrderDetails = dsTestOrders.Tables("OrderDetails") BmOrders = Me.BindingContext(dsTestOrders, "Orders") BmOrderDetails = Me.BindingContext(dsTestOrders, "Orders.OrdersOrderDetails") OrderDetailsHasChange = True SubTotal = dsTestOrders.Tables("Orders").Columns("SubTotal") SubTotal.DefaultValue = 0 Price = dsTestOrders.Tables("OrderDetails").Columns("Price") Price.DefaultValue = 0 End Sub Private Sub FillData() dsTestOrders.EnforceConstraints = False daOrders.Fill(dsTestOrders) daOrderDetails.Fill(dsTestOrders) dsTestOrders.EnforceConstraints = True End Sub Private Sub dtOrderDetails_ColumnChanged(ByVal sender As Object, ByVal e As System.Data.DataColumnChangeEventArgs) _ Handles dtOrderDetails.ColumnChanged Dim drOrders As DataRow Dim drOrderDetails As DataRow Dim iSubTotal As Integer Try If OrderDetailsHasChange Then OrderDetailsHasChange = False drOrders = dsTestOrders.Tables("Orders").Rows(BmOrders.Position) iSubTotal = 0 For Each drOrderDetails In drOrders.GetChildRows("OrdersOrderDetails")
iSubTotal = iSubTotal + drOrderDetails("price") Next drOrders.BeginEdit() drOrders("SubTotal") = iSubTotal drOrders.EndEdit() End If Finally OrderDetailsHasChange = True End Try End Sub Private Sub bndelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bndelete.Click If BmOrders.Count > 0 Then BmOrders.RemoveAt(BmOrders.Position) End If
End Sub Private Sub bncancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bncancel.Click BmOrders.CancelCurrentEdit() End Sub End C
|