where子句中的presto-static日期和时间戳

Question

我很确定以下查询在Presto上适用：

select segment, sum(count)
from modeling_trends
where segment='2557172' and date = '2016-06-23' and count_time between '2016-06-23 14:00:00.000' and '2016-06-23 14:59:59.000';
group by 1;

现在，当我运行它（在EMR上的Presto0.147上）时，我得到了一个尝试将varchar分配给日期/时间戳的错误。

我可以使用以下方法使其工作：

select segment, sum(count)
from modeling_trends
where segment='2557172' and date = cast('2016-06-23' as date) and count_time between cast('2016-06-23 14:00:00.000' as TIMESTAMP) and cast('2016-06-23 14:59:59.000' as TIMESTAMP)
group by segment;

但感觉很脏...有没有更好的办法做到这一点？

Answer 1

与其他一些数据库不同，Presto不会自动在varchar和其他类型之间进行转换，即使对于常量也是如此。强制转换起作用,但更简单的方法是使用类型构造函数：

WHERE segment = '2557172'
  AND date = date '2016-06-23'
  AND count_time BETWEEN timestamp '2016-06-23 14:00:00.000' AND timestamp '2016-06-23 14:59:59.000'

您可以在这里看到各种类型的示例：https://prestosql.io/docs/current/language/types.html