我有一个与学生（学生=1）的数据集，我需要每周监控这些学生。如何筛选特定日期的数据，然后在7天后和14天后对其进行监视？像这样的。只有这一部分起作用： (CASE WHEN (student = 1) and (start_date = '2015-04-01 00:00:00') THEN 1 ELSE 0 END) AS date_to_monitor, I think the date_add`给了夫人格里夫，因为它是在抱怨布尔类型

Select *,
(CASE WHEN (student = 1) and (start_date = '2015-04-01 00:00:00') THEN 1 ELSE 0 END) AS date_to_monitor,
(CASE WHEN (student= 1) and (date_add(start_date = '2018-11-01 00:00:00' , 7)) THEN 1 ELSE 0 END) AS date_to_monitor,
(CASE WHEN (student= 1) and (date_add(start_date = '2018-11-01 00:00:00' , 14)) THEN 1 ELSE 0 END) AS date_to_monitor,
from old;