thomasthaddeus

SELECT purchase_id, DATE(purchase_date, '7 days')
FROM purchases;

SELECT STRFTIME('%H', purchase_date)
FROM purchases;

SELECT date, (CAST(high AS 'REAL') +
  CAST(low as 'REAL')) / 2.0 AS 'average'
FROM weather
;

thomasthaddeus

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 (