Improve error management in CreateView node

We can discard the error if it was thrown because the view does not exist. But
we don't know if the Delete function will throw different errors in the
future, so it is safer to discard only the one we are sure about.

Signed-off-by: Alejandro García Montoro <alejandro.garciamontoro@gmail.com>

Author: agarciamontoro

sql/plan/create_view.go

@@ -62,12 +62,16 @@ func (create *CreateView) Resolved() bool {
 // empty.
 func (create *CreateView) RowIter(ctx *sql.Context) (sql.RowIter, error) {
 	view := sql.NewView(create.Name, create.Child)
+	registry := create.Catalog.ViewRegistry
 
 	if create.IsReplace {
-		_ = create.Catalog.ViewRegistry.Delete(create.database.Name(), view.Name())
+		err := registry.Delete(create.database.Name(), view.Name())
+		if err != nil && !sql.ErrNonExistingView.Is(err) {
+			return sql.RowsToRowIter(), err
+		}
 	}
 
-	return sql.RowsToRowIter(), create.Catalog.ViewRegistry.Register(create.database.Name(), view)
+	return sql.RowsToRowIter(), registry.Register(create.database.Name(), view)
 }
 
 // Schema implements the Node interface. It always returns nil.