--插入截至到昨天的连续随机日期到表t
DECLARE @start_date datetime;
DECLARE @insert_date datetime;
DECLARE @today datetime = getdate();

SET @start_date = CAST ( (CONVERT(varchar(7),GETDATE(),120)+'-01') AS datetime);
SET @start_date = DATEADD(hour,13,@start_date);
SET @insert_date = @start_date    

SET @insert_date = @insert_date + rand() * 1.0/24

--当下一条要插入的数据小于当前日期执行
WHILE   DATEPART(day,@insert_date) < DATEPART(day,@today)
BEGIN
    INSERT INTO t VALUES ( @insert_date,'有' );
    --准备15:00-16:00的数据
    SET @insert_date =CAST(  CONVERT(varchar(10),@insert_date,120) as datetime);
    SET @insert_date = DATEADD(HOUR,15,@insert_date);
    SET @insert_date = @insert_date + rand() * 1.0/24

    INSERT INTO t VALUES ( @insert_date,'无' );
    --准备第二天的数据
    SET @insert_date = DATEadd(day,1,CAST(  CONVERT(varchar(10),@insert_date,120) as datetime));
    SET @insert_date = DATEADD(HOUR,13,@insert_date);
    SET @insert_date = @insert_date + rand() * 1.0/24

END
GO