Teradata SQL

Customer Table: CS_Name (Primary Key), CS_Number, CS_Type

Product Table: PO_ID (Primary Key), CS_Number (Primary/Foreign Key), PO_Date (Primary Key), PO_QTY, PO_AMOUNT, PO_Note

Question: List the ucstomer name and total order amount by customer name only if this total order amount is above 4000. List the results in reverse alphabetical order by customer name.