By default SSRS adds a new database field to the detail section in a blank report as
Expr=Sum(Fields!ShipVia.Value, "Orders") or as
Expr=First(Fields!ShipVia.Value, "Orders")
Why is that? It is clear that one does mostly not want only the first or the sum, but the database field instead.
Every field I added I had to adjust it myself to
Expr=Fields!ShipVia.Value
That should be the default in my opinion. Everything else is extra work / an extra problem to solve.
