环境:SQLServer 2005 Express
1 select cast(round(6562.5,0) as int)
--result:6563
2.select round(4687.5,0),round(6562.5,0)
--result:4688.0, 6563.0
3.select round(6562.523,2)
--result:6562.520
4. select round(6562.523,-2)
--result:6600.000
round函数四舍五入,它不会减小小数位数如:6562.523 它只会把后面的3用0代替。