Thanks for answer, but if i understand your code example properly you
suugest to bind 1st datagrid with table People
> // Let us bind the people grid first
> peopleGrid.DataSource = ds.Tables["People"];
and 2nd datagrid with dataview based on Contacts table:
> // a DataView object from Contacts table to filter on the specified person
ID,
> contactsGrid.DataSource = ds.Tables["Contacts"].DefaultView;
This is not what i want achive, that way in 1st datagird i will have Name of
persons and in 2nd datgrid only Id-s.
I want in 2nd datagrid also display names of person.
I think your code can be used to display Parent/Child relation but this can
be achived easier without using datview and filtering
if i declare DataRelation in DataSet:
// declaring relation
DataRelation dr = new DataRelation("relation",
ds.Tables["People"].Columns["Id"], ds.Tables["Contacts"].Columns["Id"]);
// adding relation to dataset
ds.Relations.Add(dr);
//binding people grid
peopleGrid.SetBinding(ds, "People");
//binding contactsgrid
contactsGrid.SetBinding(ds,"relation");
i should get the same effect.
But as i said this diplay names in first grid and only id in 2nd grid, i
tried to do that using dataView,
My idea was to declare 2 relations:
// declaring relation
DataRelation dr1 = new DataRelation("r1", ds.Tables["People"].Columns["Id"],
ds.Tables["Contacts"].Columns["Id"]);
DataRelation dr2 = new DataRelation("r2", ds.Tables["People"].Columns["Id"],
ds.Tables["Contacts"].Columns["IdFriend"]);
DataView dv = new DataView(ds.Tables["People"]);
dv.RowFilter = "Child(r2).Id = " +
ds.Tables["People"].Rows[cm.Position]["Id"].ToString();
But unfortunately Child word in RowFilter expression can be used only in
aggregat functions, because it must reference to only one row. For example:
dv.RowFilter = "Max(Child(r2).Id) = " +
ds.Tables["People"].Rows[cm.Position]["Id"].ToString();
Of course this again is not what i want to get.
I am not sure if i explained my problem correctly because i dont speak
english very good. I try to make an example with data:
Table People:
Id Name
0 person A
1 person B
2 person C
3 person D
Table Contacts:
Id IdFriend
0 1
0 2
2 1
2 3
3 1
And what i want to be displayed in datagrids:
-------------------------------
1st Datagrid
0 person A <- selected row
1 person B
2 person C
3 person D
2nd DataGrid
1 person B
2 person C
---------------------------
1st Datagrid
0 person A
1 person B <- selected row
2 person C
3 person D
2nd DataGrid
Empty
----------------------------
1st Datagrid
0 person A
1 person B
2 person C <- selected row
3 person D
2nd DataGrid
1 person B
3 person D
-----------------------------
1st Datagrid
0 person A
1 person B
2 person C
3 person D <- selected row
2nd DataGrid
1 person B
-----------------------------
Any other ideas ?
Adam
Użytkownik "Ahmed Ghozzy" <(E-Mail Removed)> napisał w
wiadomości news:C6266180-0131-4FE0-ABEB-(E-Mail Removed)...
> although i have concerns on the tables design you made, but this is not
your
> problem now, so .. directly go to your problem :
> You can bind the first grid to People table normaly , and bind the second
> grid to a DataView from contacts table with filters applied to specific
> person ID, and this filter should be updated when selection changed in
people
> grid
>
> Code Sample:
> ------------------
>
> // Say your DataSet name is "ds" and it is a member in the class
>
> Metohd/Constructor Scope
> {
> // Let us bind the people grid first
> peopleGrid.DataSource = ds.Tables["People"];
>
> // To track the selected position of the selected row of people table we
use
> // currency manager object
> CurrencyManager cm = (CurrencyManager)
> this.BindingContext[ds.Tables["People"]];
>
> // Let us subscribe to the event of changing the position
> cm.PositionChanged += new EventHandler(cm_PositionChanged);
>
> // Now, bindng the contacts grid to a special edition of the contacts
table
> using
> // a DataView object from Contacts table to filter on the specified person
ID,
> contactsGrid.DataSource = ds.Tables["Contacts"].DefaultView;
> // Note that you can create new DataView object instead of using
DefaultView,
> // but it is bad to create a new object for each user click on the people
> grid!!
>
> // Now, the DataView Filter
> ds.Tables["Contacts"].DefaultView.RowFilter = "Id = " +
> ds.Tables["People"].Rows[cm.Position]["Id"].ToString();
>
> }
>
> // The event handler to changing position, just to update the Default view
> filter
> private void cm_PositionChanged(object sender, EventArgs e)
> {
> ds.Tables["Contacts"].DefaultView.RowFilter = "Id = " +
> ds.Tables["People"].Rows[cm.Position]["Id"].ToString();
> }
>
> Hope this be useful for you, good luck
> --
> Ahmed Ghozzy
>
>
> "Bachus" wrote:
>
> > Hello,
> > I have following problem. I have dataSet with two tables, containing
data
> > about some people and a relation describing connections between these
> > people:
> >
> > People:
> > Id
> > Name
> >
> > Contacts:
> > Id
> > IdFriend
> >
> > This is many - to - many relation, every person can have many friends
and
> > every person can be a friend of many. I have primary key on People.Id
and on
> > Contacts.Id, Contacts.IdFriend, and two relations:
> > People.Id - Contacts.Id and People.Id - Contacts.IdFriend
> > I want to display two dataGrids, one with list of all people, second one
> > with list of friends of person selected in first datagrid. Can anyone
give
> > me some suggestion how to do that ?
> >
> > Thanks,
> > Adam
> >
> >
> >
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