Hi! how do get the number of students who atteded the prep with the last 1 hour.

CREATE TABLE [dbo].[PrepTime] (
[ID] [int] IDENTITY (1, 1) NOT NULL ,
[PrepNo] [int] NOT NULL ,
[Log_Time] datetime NOT NULL DEFAULT, CURRENT_TIMESTAMP,
[coming] [int] NULL ,
[going] [int] NULL ,
[Student_ID] [bigint] NULL ,
[Study_Type] [int] NULL ,
[State] [smallint] NULL

) ON [PRIMARY]
GO