小编Hoa*_*Nam的帖子

我有第一个查询

select count(*)
from `order`
where marketer_id = 75 and
      HandleStatus != -1 and
      (Created_at BETWEEN '2017-05-01' AND '2017-05-31')

结果是1050

我还有第二个问题:

select count(*)
from `order`
where marketer_id = 75 and
      HandleStatus != -1 and
      (Month(Created_at) =5 and Year(Created_at) = 2017)

结果是1111

我认为2个查询具有相同的含义,但它返回2个不同的结果.有关"Created_at"列的信息:COLUMN_NAME Created_at,COLUMN_TYPE时间戳,IS_NULLABLE NO,COLUMN_KEY,COLUMN_DEFAULT CURRENT_TIMESTAMP

请帮忙2查询有什么区别？