啊各位大侠救命

在线等啊，各位大侠救命！

select   datediff( "h ",select   Vis_Time   from   NS_Visitors   where   vis_userid   =2152,getdate())
错了，不知道错在哪里？

[解决办法]
select datediff(hh,(select Vis_Time from NS_Visitors where vis_userid =2152),getdate())