问题是：
首先介绍一下表。有2个表：1.PropertyTable（资产表）、2.ContractTable（合同表）。以前两个表中都有City(所在城市)、Road（所在路段）、Address（门牌号），ContractTable中的City、Road、Address的外键是PropertyTable中的City、Road、Address（ContractTable中的City、Road、Address来源于PropertyTable）。
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以前我是通过where ContractTable.City+ContractTable.Road+ContractTable.Address=PropertyTable.City+PropertyTable.Road+PropertyTable.Address的条件来联系两个表的，但这样在实际操作中比较麻烦。所以，我给PropertyTable添加了一个PropertyTableID，并把这个PropertyTableID设置为主键。然后我又给ContractTable添加了一个新的列ContractTableID，通过where
ContractTable.City+ContractTable.Road+ContractTable.Address=PropertyTable.City+PropertyTable.Road+PropertyTable.Address的条件把PropertyTableID的值赋给ContractTableID，以后就可以用where ContractTable.ContractTableID=PropertyTable.PropertyTableID的条件来联系两个表了。
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现在的问题是，我使用前台程序打开ContractTableAdd.aspx,添加新合同，怎么样可以在选择了City、Road、Address后，在点击‘确定’时自动在ContractTable中给添加的新合同增加相应的ContractTableID呢？？？
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附带说一下，我用的是LinqToSQL！
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下面是前台和后台程序。我觉得应该是在后台添加吧！？请各位不吝解答！！！谢谢！
======================部分前台代码=======================
<td>
<asp:SqlDataSource ID="SqlDataSource_Road" runat="server"
ConnectionString="<%$ ConnectionStrings:长铁物业公司资产数据库ConnectionString %>"
SelectCommand="SELECT DISTINCT [Road] FROM [PropertyTable] WHERE ([City] = @City) and propertystate='1'">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList_City" Name="City"
PropertyName="SelectedValue" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
</td>
<td>
<asp:SqlDataSource ID="SqlDataSource_Address" runat="server"
ConnectionString="<%$ ConnectionStrings:长铁物业公司资产数据库ConnectionString %>"
SelectCommand="SELECT [Address] FROM [PropertyTable] WHERE (([City] = @City) AND ([Road] = @Road)) and propertystate='1'">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList_City" Name="City"
PropertyName="SelectedValue" Type="String" />
<asp:ControlParameter ControlID="DropDownList_Road" Name="Road"
PropertyName="SelectedValue" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
</td>
========================后台代码======================
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;
public partial class ContractTable_ContractAdd : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button_Submit_Click(object sender, EventArgs e)
{
if (Page.IsValid)
{
DataClassesDataContext db = new DataClassesDataContext();
ContractTable myct = new ContractTable();
myct.ContractNumber = TextBox_ContractNumber.Text.ToString();//合同编号
myct.ContractTypeDetail = TextBox_ContractTypeDetail.Text.ToString();//合同种类（详细）
myct.ContractType = DropDownList_ContractType.SelectedItem.Value.ToString();//合同类型
myct.SumbitNumber = TextBox_SubmitNumber.Text.ToString();//送审编号
myct.SubjectMatter = TextBox_SubjectMatter.Text.ToString();//标的物
//City、Road、Address为必填项
myct.City = DropDownList_City.SelectedItem.Value.ToString();
myct.Road = DropDownList_Road.SelectedItem.Value.ToString();
myct.Address = DropDownList_Address.SelectedItem.Value.ToString();
myct.OppositeSide = TextBox_OppositeSide.Text.ToString();//合同相对方
myct.ManageProject = TextBox_ManageProject.Text.ToString();//经营项目
if (TextBox_LeaseDateSign.Text!="")//合同签订日
myct.LeaseDateSign = Convert .ToDateTime(TextBox_LeaseDateSign.Text);
if (TextBox_LeaseDtaeFrom.Text!="")//合同起始日
myct.LeaseDateFrom = Convert.ToDateTime(TextBox_LeaseDtaeFrom.Text);
if (TextBox_LeaseDateTo.Text!="")//合同终止日
myct.LeaseDateTo = Convert.ToDateTime(TextBox_LeaseDateTo.Text);
myct.PerformState = TextBox_PerformState.Text.ToString();//合同状态
//安全协议
if (RadioButton_SafeContractYes.Checked )
myct .SafetyContract=true;
if (RadioButton_SafetyContractNo.Checked )
myct .SafetyContract =false ;
//计生协议
if (RadioButton_FamilyPlanningContractYes.Checked)
myct.FamilyPlanningContract = true;
if (RadioButton_FamilyPlanningContractNo.Checked)
myct .FamilyPlanningContract=false;
//食品安全协议
if (RadioButton_FoodContractYes.Checked)
myct.FoodContract = true;
if (RadioButton_FoodContractNO.Checked)
myct.FoodContract = false;
//添加了部门和人！！！
myct.ContractCompany = TextBox_ContractCompany.Text.ToString();//合同签订分公司
myct.ContractResponsible = TextBox_ContractResponsible.Text.ToString();//合同负责人
myct.ContractManager = TextBox_ContractManager.Text.ToString();//合同管理员
myct.ContractChange = TextBox_ContractChange.Text.ToString();//合同变更
//租金相关
if (TextBox_ReferencePrice.Text!="")//周边参考价
myct.ReferencePrice = decimal .Parse ( TextBox_ReferencePrice.Text);
myct.ReferencePriceRemarks = TextBox_ReferencePriceRemarks.Text.ToString();//参考价备注
myct.ContractRemarks = TextBox_ContractRemarks.Text.ToString();//合同备注
myct.TypeOfPayment = TextBox_TypeOfPayment.Text.ToString();//付款方式
if (TextBox_MonthRent.Text != "")//理论月租金
myct.MonthRent = decimal.Parse(TextBox_MonthRent.Text);
//if (TextBox_RealityRent.Text!="")//实收月租金
// myct.RealityRent = decimal.Parse(TextBox_RealityRent.Text);
//if (TextBox_RealityYearRent.Text != "")//实收年租金
// myct.RealityYearRent = decimal.Parse(TextBox_RealityYearRent.Text);
if (TextBox_YearRent.Text != "")//理论年租金
myct.YearRent = decimal.Parse(TextBox_YearRent .Text );
if (TextBox_SumRent.Text!="")//理论租金总金额
myct.SumRent = decimal.Parse(TextBox_SumRent.Text );
if (TextBox_LeaseAssureMoney.Text!="")//租赁保证金
myct.LeaseAssureMoney = decimal.Parse(TextBox_LeaseAssureMoney .Text );
if (TextBox_PenalSum.Text != "")//违约金
myct.PenalSum = decimal.Parse(TextBox_PenalSum .Text .ToString ());
if (TextBox_PropertyManageMoney.Text != "")//物业管理费
myct.PropertyManageMoney = decimal.Parse(TextBox_PropertyManageMoney.Text);
if (TextBox_RateOfRise.Text!="")//递增率
myct.RateOfRise = decimal.Parse(TextBox_RateOfRise .Text);
db.ContractTable.InsertOnSubmit(myct);
db.SubmitChanges();
TextBox_ContractNumber.Focus();
//清空
TextBox_OppositeSide.Text = "";
TextBox_ManageProject.Text = "";
//TextBox_LeaseDateSign.Text = "";
}
}
protected void CustomValidator_ContractNumber_ServerValidate(object source, ServerValidateEventArgs args)
{
DataClassesDataContext db = new DataClassesDataContext();
ContractTable mypt;
args.IsValid = false;
try//多个参数同时判定的写法！！！
{
mypt = db.ContractTable.Where(c => c.ContractNumber ==TextBox_ContractNumber.Text).First();
}
catch
{
args.IsValid = true;
}
}
}
C# 菜鸟中的雏鸟！提的问题也许很幼稚，但我是认真的。希望看在党国的面子上拉兄弟一把！
