Этот пример должен работать на любой версии SQL Server.
Это более многословно, чем нужно, чтобы прояснить, как оно работает.
--create test data
create table #t
(id int
,lastTime datetime
)
insert #t
select 1,dateadd(mi,-1,getdate())
union select 2,dateadd(hh,-1,getdate())
union select 3,dateadd(dd,-1,getdate())
union select 4,dateadd(mm,-1,getdate())
union select 5,dateadd(yy,-1,getdate())
union select 6,dateadd(yy,-5,getdate())
union select 7,NULL
-- carry out formatting to handle pluralisation
SELECT id
,ISNULL(lastAction,'Never')
+ CASE WHEN lastVal > 1
THEN 's ago'
WHEN lastVal = 1
THEN ' ago'
ELSE ''
END
FROM
(
-- Use coalesce to select the first non-null value from the matrix
SELECT id
,COALESCE(CAST(years as VARCHAR(20)) + ' year'
,CAST(months as VARCHAR(20)) + ' month'
,CAST(days as VARCHAR(20)) + ' day'
,CAST(hours as VARCHAR(20)) + ' hour'
,CAST(minutes as VARCHAR(20)) + ' minute'
,CAST(secs as VARCHAR(20)) + ' second'
) as lastAction
,COALESCE(years
,months
,days
,hours
,minutes
,secs
) as lastVal
FROM
(
-- create a matrix of elapsed time
SELECT id
,datediff(ss,lastTime,getdate()) secs
,NULLIF(datediff(mi,lastTime,getdate()),0) minutes
,NULLIF(datediff(hh,lastTime,getdate()),0) hours
,NULLIF(datediff(dd,lastTime,getdate()),0) days
,NULLIF(datediff(mm,lastTime,getdate()),0) months
,NULLIF(datediff(yy,lastTime,getdate()),0) years
from #t
) as X
) AS Y