Average Time Interval Between A Start And End Time

[intapiuser]

Looking to get the average time interval between a start and an end time (ex: Given the start and end times for runners in a race, find the average time it takes for a runner to complete the race)? Find exactly how to write this up in each flavor of SQL below!

Redshift

select avg(extract(epoch from endtime) - extract(epoch from starttime)) as avg_time

Postgres

select avg(endtime - starttime) as avg_time

SQL Server

select cast(cast(avg(cast((endtime - starttime) as FLOAT) - floor(cast((endtime - starttime) as FLOAT))) as datetime) as time) as 'Avg Time'

MySQL

select TIME(FROM_UNIXTIME(AVG(UNIX_TIMESTAMP(endtime) - UNIX_TIMESTAMP(starttime)))) AS AVG_TIME

BigQuery (Standard SQL)

Select TIME(TIMESTAMP_MILLIS(CAST(avg(DATETIME_DIFF(endtime,starttime,millisecond)) as INT64))) as avg_time

SQL Server solution inspired by this post