在DataSet中建立外键约束

2008-02-22 09:26:49来源：互联网阅读 ()

程序可以直接拿来使用，运行通过。

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testconstraint.aspx
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<%@ Page Language="c#" debug="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<html>
<head>
<script language="c#" runat="server">
public DataSet ds;
void Page_Load(Object sender,EventArgs e)
{
if(!IsPostBack)
{
SqlConnection myConnection = new SqlConnection("server=(local);database=northwind;Trusted_Connection=yes");
SqlDataAdapter myDataAdapter1=new SqlDataAdapter("select * from suppliers",myConnection);
SqlDataAdapter myDataAdapter2=new SqlDataAdapter("select * from products",myConnection);

ds=new DataSet();
myDataAdapter1.Fill(ds,"suppliers");
myDataAdapter2.Fill(ds,"products");

MyDataGrid.DataSource=ds.Tables["suppliers"].DefaultView;
MyDataGrid.DataBind();
MyDataGrid2.DataSource=ds.Tables["products"].DefaultView;
MyDataGrid2.DataBind();
}
}

void MyDataGrid_Delete(Object sender,DataGridCommandEventArgs e)
{
String conn="server=(local);database=northwind;Trusted_Connection=yes";
String selectCommandText1="select * from suppliers";
String selectCommandText2="select * from products";

SqlDataAdapter myDataAdapter1=new SqlDataAdapter();
myDataAdapter1.SelectCommand=new SqlCommand();
myDataAdapter1.SelectCommand.CommandText=selectCommandText1;
myDataAdapter1.SelectCommand.Connection=new SqlConnection(conn);

SqlDataAdapter myDataAdapter2=new SqlDataAdapter();
myDataAdapter2.SelectCommand=new SqlCommand();
myDataAdapter2.SelectCommand.CommandText=selectCommandText2;
myDataAdapter2.SelectCommand.Connection=new SqlConnection(conn);

ds=new DataSet();
myDataAdapter1.Fill(ds,"suppliers");
myDataAdapter2.Fill(ds,"products");

CreateConstraint();

int index=(int)e.Item.ItemIndex;
ds.Tables["suppliers"].Rows[index].Delete();
ds.Tables["suppliers"].AcceptChanges();

myDataAdapter1.Update(ds,"suppliers");

MyDataGrid.DataSource=ds.Tables["suppliers"].DefaultView;
MyDataGrid.DataBind();

MyDataGrid2.DataSource=ds.Tables["products"].DefaultView;
MyDataGrid2.DataBind();
}

void CreateConstraint()
{
DataColumn parentColumn,childColumn;
ForeignKeyConstraint myForeignKeyConstraint;

parentColumn = ds.Tables["suppliers"].Columns["supplierID"];
childColumn = ds.Tables["products"].Columns["supplierID"];
myForeignKeyConstraint = new ForeignKeyConstraint("SupplierForeignKeyConstraint", parentColumn, childColumn);

myForeignKeyConstraint.DeleteRule = Rule.Cascade ;
myForeignKeyConstraint.UpdateRule = Rule.Cascade ;
myForeignKeyConstraint.AcceptRejectRule = AcceptRejectRule.Cascade ;

ds.Tables["products"].Constraints.Add(myForeignKeyConstraint) ;
ds.EnforceConstraints =true ;
}

</script>
</head>
<body>
<form runat="server">
<ASP:DataGrid id="MyDataGrid" runat="server"
Width="800"
BackColor="#ccccff"
BorderColor="black"
ShowFooter="false"
CellPadding=3
CellSpacing="0"
Font-Name="Verdana"
Font-Size="8pt"
HeaderStyle-BackColor="#aaaadd"
OnDeleteCommand="MyDataGrid_Delete"
DataKeyField="supplierid"
>