Sum Amt and Max date of each employer

SELECT tblCustomer.Name, tblCustomer.Address, tblCustomer.Email, TblInvoice.Amt,Dateofpurchase
FROM tblCustomer INNER JOIN
TblInvoice ON tblCustomer.Cid = TblInvoice.Cid
order by TblInvoice.Cid
compute max(TblInvoice.DateOfpurchase),sum(TblInvoice.Amt) by TblInvoice.Cid