text: --1. Please pause the video and import the excel file under
  --   lesson resources
  --2. import the SalesAmount field as a money
  --3. Date import as date data type
  --4. percent change: (current amount - previous amount )/previous amount
  select SalesAmount,
  lag(SalesAmount) over(order by date) As PreviousDaylSales,
  (SalesAmount-(lag(SalesAmount) over(order by date))) as Difference,
  (SalesAmount-(lag(SalesAmount) over(order by date)))/(lag(SalesAmount) over(order by date))*100
  as PercentChange
  from Sheet1$
  
  
  