sqlserver求标准偏差,oracle求标准偏差

oracle 求标准偏差:
select  STDdEV(column1) from (
select 50 column1 from dual
union
select 90  from dual
union
select 70  from dual) tt


sqlserver 里求标准偏差:
select  STDEV(column1) from (
select 50 column1
union
select 90 
union
select 70 ) tt