Adding IsNotNull and ViewFields in CAML Query

Question

Trying to add IsNotNull parameter and ViewFields paramter but throwing an error. Am I inserting incorrectly or missing something to make sure this executes correctly? Seems like View is bring back all of the items in the list and just need the item I was original returning before needing to add these other parameter

                       SPQuery myquery = new SPQuery();
                        myquery.Query =
                        "<View>" +
                            "<Where>" +
                            "<And>" +
                                "<Contains>" +
                                    "<FieldRef Name='Group' />" +
                                    "<Value Type='Text'>City</Value>" +                                  
                                "</Contains>" +
                                "<Eq>" +
                                    "<FieldRef Name='System' />" +
                                    "<Value Type='Text'>" + Param.var.ToString() + "</Value>" +
                                "</Eq>" +
                                "<And>" +
                                "<IsNotNull>" +
                                    "<FieldRef Name='Email' />" +
                                "</IsNotNull>" + 
                                "</And>" +
                                "<ViewFields>" +
                                    "<FieldRef Name='Email' />" +
                                "</ViewFields>" +
                            "</And>" +
                            "</Where>" +
                        "</View>";

Answer 1

You don't use ViewFields inside the Where clause in a CAML query. See Query Schema and SPQuery.ViewFields Property

Also, the And around the IsNotNull node is doing nothing. The And needs two child elements to operate correctly.