DataRelation Check?

  • Thread starter Thread starter localhost
  • Start date Start date
L

localhost

I have a DataSet with 4 DataRelations inside. For each DataRelation,
I need to enumerate the tables from "bottom up". Some DataRelations
are parent-child, others are parent-child-grandchild. How can I make
a single "recursive function" to tell me which tables belong to
others?

Thanks.
 
You don't eally need to recurse, since all the DataRelations are contained in
the DataSet's Relarions Collection:

Dim ds As DataSet
Dim dr As DataRelation
For Each dr In ds.Relations
Dim ParentCol As DataColumn = dr.ParentColumns(0)
Dim ParentTable As DataTable = ParentCol.Table

Dim ChildCol As DataColumn = dr.ChildColumns(0)
Dim ChildTable As DataTable = ChildCol.Table

Console.WriteLine("Relation: " & dr.RelationName & " Parent: " &
ParentTable.TableName & " Child: " & ChildTable.TableName)
Next dr

But you said you wanted to go bottom-up. I don't know exactly where your
starting point should be, but given a single DataTable, this function will
recursively identify parents, grandparents, etc.

Private Function GetMyParent(ByVal dt As DataTable)
Dim dr As DataRelation
For Each dr In dt.ParentRelations
Dim ParentCol As DataColumn = dr.ParentColumns(0)
Dim ParentTable As DataTable = ParentCol.Table
Console.WriteLine("Child Table: " & dt.TableName & " Parent: "
& ParentTable.TableName)
GetMyParent(ParentTable)
Next
End Function

HTH
 
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