I have two tables, Merged_Stock and I_Products. I_Products has a field 'stock_code'. Merged_Stock has two fields, 'old_stock_code' and 'new_stock_code'. I want to write a query which updates I_Products.stock_code with Merged_Stock.new_stock_code. Records will be matched on I_Products.stock_code = Merged_Stock.old_stock_code