获取日期之间的数据使用情况

Question

我有查询来获取cost_month/月的数据，如下所示：

select sum(xscf_cost_month) as cost_month
from ncloud_data_service_cof a
join ncloud_data_ba b on b.xcba_cof_no = a.xscf_cof_no
where to_time('2014-05', 'YYYY-mm') between to_char(b.xcba_activation_date, 'YYYY-mm') and to_char(b.xcba_end_activation_date, 'YYYY-mm')

上面的查询显示错误：“错误：操作员不存在：日期

如何修复它？我试图改变to_charto_time但没有得到解决方案。

Answer 1

这个仍然可以在列b.xcba_activation_date和b.xcba_end_activation_date上使用索引：

SELECT sum(xscf_cost_month) as cost_month
FROM ncloud_data_service_cof a 
     JOIN
         ncloud_data_ba b ON b.xcba_cof_no = a.xscf_cof_no
WHERE to_time('2014-05', 'YYYY-mm') BETWEEN date_trunc('month', b.xcba_activation_date) AND date_trunc('month', b.xcba_end_activation_date);

Answer 2

你打算这样做吗？

select sum(xscf_cost_month) as cost_month
from ncloud_data_service_cof a join
     ncloud_data_ba b
     on b.xcba_cof_no = a.xscf_cof_no
where '2014-05' between to_char(b.xcba_activation_date, 'YYYY-mm') and 
                        to_char(b.xcba_end_activation_date, 'YYYY-mm');

您不需要转换字符串'2014-05'。它已经是一个字符串。