I tried that and but the root level expression could not find the expression int the
List Table.
Jon Stonecash wrote:
> I do not know if this is what you want or that it will work. Why not put an
> expression in the List table columns to sum the items in the list. Then
> modify your sum of list items to sum the sum.
>
> Jon Stonecash
>
> >From: Doug finke <[EMAIL PROTECTED]>
> >Reply-To: "Moderated discussion of advanced .NET topics."
> ><[EMAIL PROTECTED]>
> >To: [EMAIL PROTECTED]
> >Subject: [ADVANCED-DOTNET] ADO.NET Parent/Child Relation Referencing
> >Date: Thu, 19 Dec 2002 05:58:20 -0800
> >
> >How deep can you reference with Parent/Child Relation Referencing?
> >
> >I have three tables to relate, the first table is clients, the second
> >table is how many lists each has and the third table holds the items of
> >each list.
> >
> >In the client table I create a column and set it's expression to count how
> >many lists that client has, no problem. An error occurs when I want to sum
> >the items Amount in that list.
> >
> >
> >
> >System.Data.SyntaxErrorException: Syntax error in aggregate argument:
> >Expecting a single column argument with possible 'Child' qualifier.
> > at System.Data.ExpressionParser.ParseAggregateArgument(FunctionId
> >aggregate)
> > at System.Data.ExpressionParser.Parse()
> > at System.Data.DataExpression..ctor(String expression, DataTable
> >table,
> >Type type)
> > at System.Data.DataColumn.set_Expression(String value)
> > at testRelationsError.Form1.Build() in
> >c:\temp\testrelationserror\form1.cs:line 129
> > at testRelationsError.Form1.Form1_Load(Object sender, EventArgs e) in
> >c:\temp\testrelationserror\form1.cs:line 95
> > at System.Windows.Forms.Form.OnLoad(EventArgs e)
> > at System.Windows.Forms.Form.OnCreateControl()
> > at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
> > at System.Windows.Forms.Control.CreateControl()
> > at System.Windows.Forms.Control.WmShowWindow(Message& m)
> > at System.Windows.Forms.Control.WndProc(Message& m)
> > at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
> > at System.Windows.Forms.ContainerControl.WndProc(Message& m)
> > at System.Windows.Forms.Form.WmShowWindow(Message& m)
> > at System.Windows.Forms.Form.WndProc(Message& m)
> > at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
> > at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
> > at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg,
> >IntPtr wparam, IntPtr lparam)
> >
> >
> > void Build()
> > {
> > DataSet ds = new DataSet();
> >
> > ds.Tables.Add(new DataTable());
> > ds.Tables.Add(new DataTable());
> > ds.Tables.Add(new DataTable());
> >
> > ds.Tables[0].Columns.Add("ClientID", typeof(int));
> > ds.Tables[0].Columns.Add("ClientName");
> >
> > ds.Tables[1].Columns.Add("ClientID", typeof(int));
> > ds.Tables[1].Columns.Add("ListID", typeof(int));
> > ds.Tables[1].Columns.Add("ListName");
> >
> > ds.Tables[2].Columns.Add("ListID", typeof(int));
> > ds.Tables[2].Columns.Add("Amount", typeof(int));
> > ds.Tables[2].Columns.Add("Ticker");
> >
> > PopulateData(ds);
> >
> > ds.Relations.Add("Lists", ds.Tables[0].Columns["ClientID"],
> >ds.Tables[1].Columns["ClientID"]);
> > ds.Relations.Add("ListDetail", ds.Tables[1].Columns["ListID"],
> >ds.Tables[2].Columns["ListID"]);
> >
> > DataColumn dc =null;
> >
> > dc = new DataColumn("# in List");
> > dc.Expression = "Count(Child(Lists).ListID)";
> > ds.Tables[0].Columns.Add(dc);
> >
> > dc = new DataColumn("Total Amount");
> > dc.Expression = "Sum(Child(Lists)(ListDetail).Amount)";
> > ds.Tables[0].Columns.Add(dc);
> >
> > dataGrid1.DataSource = ds;
> > dataGrid1.DataMember = "Table1";
> > }
> >
> > void PopulateData(DataSet ds)
> > {
> > Random r = new Random();
> > DataRow dr = null;
> > int ListID = 0;
> >
> > for(int i = 0; i < 5; i++)
> > {
> > dr = ds.Tables[0].NewRow();
> > dr["ClientID"] = i;
> > dr["ClientName"] = "Client " + i;
> > ds.Tables[0].Rows.Add(dr);
> >
> > for(int j = 0; j < r.Next(1,10); j++)
> > {
> > dr = ds.Tables[1].NewRow();
> > dr["ClientID"] = i;
> > dr["ListID"] = ListID;
> > dr["ListName"] = "List " + j;
> > ds.Tables[1].Rows.Add(dr);
> >
> > for(int k = 0; k < r.Next(1,10); k++)
> > {
> > dr = ds.Tables[2].NewRow();
> > dr["ListID"] = ListID;
> > dr["Amount"] = r.Next(1000,2000);
> > dr["Ticker"] = "Ticker " + k;
> > ds.Tables[2].Rows.Add(dr);
> > }
> >
> > ListID++;
> > }
> > }
> > }
> >
> >You can read messages from the Advanced DOTNET archive, unsubscribe from
> >Advanced DOTNET, or
> >subscribe to other DevelopMentor lists at http://discuss.develop.com.
>
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