DATASET and CHildrecords

[Vandy02]

I have a dataset with two tables..."DEPT", "EMP"
They have column "DEPTNO" in common...
I have made a relation and tied the dataset to a datagrid "dgDEPT" and the relationship works.

What I want to do is have a grid as the DEPT table and when I select on a record...I want a separate grid to show the child records...any idea?

At present dgDEPT shows the DEPT records and has "+" so I can look at the child records
=====================================================
Dim strEMP, strDEPT As String
strEMP = "Select * from EMP"
strDEPT = "Select * from DEPT"

Dim dsEMP = New DataSet


Dim daEMP = New OleDb.OleDbDataAdapter(strEMP, conn)
Dim daDEPT = New OleDb.OleDbDataAdapter(strDEPT, conn)

daEMP.Fill(dsEMP, "EMP")
daDEPT.Fill(dsEMP, "DEPT")
conn.Close()

'EXAMPLE OF MANUAL BINDING

dsEMP.Relations.Add("MINE", dsEMP.Tables("DEPT").Columns("DEPTNO"), dsEMP.Tables("EMP").Columns("DEPTNO"))

dgDEPT.SetDataBinding(dsEMP, "DEPT")

==============================================

thanks

 

[Ragnarox]

Vandy02,

In order to get the second datagrid to show the child records for the main grid selection you may want to try this. Instead of getting 2 tables, make 1 table as a join of the two. The set each datagrids table style and column style to show only the information that you want. Then set each grids datasource to that table. This should allow a selection in 1 to bring up the corresponding row in the other.

Hope this helps,

Brian

 

[RiverGuy]

Ragnarox,
That solution does not work, because if you do a join in SQL, you will get duplicate records that he wants to show in his parent table.

Any how, there is an article to do exactly what Vandy02 needs to do.

http://msdn.microsoft.com/library/d...btskcreatingmasterdetailslistwithdatagrid.asp

 

[Vandy02]

This is what I obtained from the link..
However, when I use mine I get an error...

"Overload resolution failed because no accessible 'NEW'
can be called without narrowing conversion"

Can someone try this...

' Visual Basic
Dim myDataRelation As DataRelation
myDataRelation = New DataRelation _
("CustOrd", ds.Tables("Customers").Columns("CustomerID"), _
ds.Tables("Orders").Columns("CustomerID"))
' Add the relation to the DataSet.
ds.Relations.Add(myDataRelation)
GridOrders.SetDataBinding(ds, "Customers")
GridDetails.SetDataBinding(ds, "Customers.CustOrd")


=====MINE
Dim strEMP, strDEPT As String
strEMP = "Select * from EMP"
strDEPT = "Select * from DEPT"

Dim daEMP = New OleDb.OleDbDataAdapter(strEMP, oOleDbConnection)
Dim daDEPT = New OleDb.OleDbDataAdapter(strDEPT, oOleDbConnection)
daEMP.Fill(ds, "EMP")
daDEPT.Fill(ds, "DEPT")
oOleDbConnection.Close()
dgDEPT.SetDataBinding(ds, "DEPT") 'to make sure table is obtained --good
dgEMP.SetDataBinding(ds, "EMP") 'to make sure table is obtained -good

'EXAMPLE OF MANUAL BINDING

Dim myDataRelation As DataRelation

myDataRelation = New DataRelation("DEPTLIST", ds.Tables("DEPT").Columns("DEPTNO"), _
ds.Tables("EMP").Columns("DEPTNO"))

 

[RiverGuy]

I'm not sure about that one. You might try referencing the Tables and Columns by index rather than string name.

 

[Vandy02]

well, i tried this and at least i get to the form this time...but i get another error...i changed the format so I could get to the form...any idea with the error?


myDataRelation = New DataRelation("DEPTLIST", ds.Tables(0), ds.Tables(0).Columns("DEPTNO"), ds.Tables(1), ds.Tables(1).Columns("DEPTNO"), True)

An unhandled exception of type 'System.InvalidCastException' occurred in microsoft.visualbasic.dll

Additional information: Cast from type 'DataTable' to type 'String' is not valid.