Window Functions in SQL

streams.sqlite

SELECT
   artist,
   week,
   streams_millions,
   streams_millions - LAG(streams_millions, 1, streams_millions) OVER ( 
      PARTITION BY artist
      ORDER BY week 
   ) AS 'streams_millions_change',
   chart_position,
   LAG(chart_position, 1, chart_position) OVER (
     PARTITION BY artist
     ORDER BY week
   ) - chart_position AS 'chart_position_change'
FROM
   streams 
WHERE
   artist = 'Lady Gaga';