格式化两位小数，SQL去掉星期六星期天，内存流来深拷贝

Code
取小数点两位
m.ToString("0.00"));

--用日期相减时除去星期天,得到日期相减天数
declare @x datetime,@y datetime
set @x='2009-7-1'
set @y='2009-7-31'
set datefirst 1
if datepart(dw,@X)<>7
begin
select datediff(day,@x,@y)-datediff(week,@x,@y)
end
else
begin
select datediff(day,@x,@y)-datediff(week,@x,@y)-1
end

利用内存流来进行深拷贝, 不过obj要加上[Serializable]
public static object DeepCopy(object obj)
{
MemoryStream ms = new MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(ms, obj);

object retval;
ms.Seek(0, SeekOrigin.Begin);
retval = bf.Deserialize(ms);
ms.Close();
return retval;
}