Question

I have data like date, name, counts

How can I get the date interval between the first and the last date of each name?

SELECT name, SUM(counts), MAX(date)-MIN(date) AS age //this is wrong
FROM tb
GROUP BY name

Answer 1

SELECT name
     , SUM(counts)
     , DATEDIFF(MAX(date), MIN(date))/365 AS age1  --- may need adjustment
     , YEAR(MAX(date)) - YEAR(MIN(date))  AS age2  --- integer result
FROM tb
GROUP BY name