Recalculate DataSet Computed Column

[Guest]

Hi
I have some troubles with a computed column in a DataSet
I have a typed DataSet ds, which is received from a WebService ws. The Table BestillingslisteLinie has one child-relation to the table BestillingslisteLinieKommentar
My computed column is added to the table BestillingslisteLinie like this
DataSet ds; //declared private to the clas
..
public dsBestilling HentBestillinger()
ds = ws.GetBestillingslister()
DataColumn col = new DataColumn("HarKommentar")
col.DataType = System.Type.GetType("System.Boolean")
col.Expression = "Count(Child.ID)"
ds.BestillingslisteLinie.Columns.Add(col)


This works fine - no problem. However, when I then later merge another DataSet with the same structure into ds, the computed column do not get recalculated.
I have some code which calls another WebService and then merges the returned DataSet into the existing DataSet ds like this
public dsBestiling Valider(int ID)
dsBestillingsliste dsMerge = ws.ValiderBestillingsliste(ID)
dsBestilling.Merge(dsMerge)

Do anyone know how to get the computed column to recalculate itself. By now the column always contains false on merged rows, although it should be true

Thanks
Mogens

 

[Val Mazur]

Hi,

Why are you using Boolean datatype to get rows count? try to declare it as
Integer and it should be calculated properly.