(year, '2020-05-01', getdate())
print datediff(month, '2020-05-01', getdate())
print datediff(day, '2020...-05-01', getdate())
print datediff(hour, '2022-03-31', getdate())
print datediff(minute, convert(datetime...())
本周星期一 至 星期日
SELECT DATEADD(wk, DATEDIFF(wk,0,getdate()), 0) --本周星期一
SELECT DATEADD(wk, DATEDIFF(wk...DATEDIFF(wk,0,getdate()), 3) --本周星期四
SELECT DATEADD(wk, DATEDIFF(wk,0,getdate()), 4) --本周星期五
SELECT DATEADD...(wk, DATEDIFF(wk,0,getdate()), 5) --本周星期六
SELECT DATEADD(wk, DATEDIFF(wk,0,getdate()), 6) --本周星期日
上n周的星期一