MySQL datetime类型字段查询方式

MySQL中查询datetime类型的字段时，直接使用时间字符串和比较运算符即可。

SELECT * from orders WHERE create_at >= '2021-01-01';

SELECT * from orders WHERE created_at >= '2021-01-01 00:00:00' AND created_at <= '2021-01-31 23:59:59';

SELECT * from orders WHERE create_at >= '2021-01-01' AND created_at < '2021-02-01';

查询范围也可以使用 between 运算符：

SELECT * from od WHERE create_time between '2021-01-01 00:00:00' and '2021-01-01 23:59:59';