SQL：结合大小写和数字到日期的转换

Question

我想做一个 sql 语句，它在一个 table 中计算 2 个日期值的减法。如果该值为负数，我只想将其显示为 0 值。

数值是付款处于当前状态的秒数。我用一个技巧将它转换为时间值（日期类型）。

我当前的代码是

SELECT 
max(CASE WHEN t1.time_event < SYSDATE and t2.time_event > SYSDATE THEN to_char(to_date(max(round(SYSDATE - t1.time_event) * 24 * 60 * 60)),'ssssss'),'hh24:mi:ss') else to_char(to_date(0)) END) as "current_age"
from tbl_dummyfeed t1 join tbl_dummyfeed t2 on t1.payment_Id = t2.payment_id
where t1.event = 'accepted' and t2.event = 'enriched');

Answer 1

这行得通，只需要转换为时间 hh24:mi:ss。

SELECT max(CASE WHEN t1.time_event < SYSDATE and t2.time_event > SYSDATE THEN round((SYSDATE - t1.time_event) * 24 * 60 * 60) else 0 END) as "current_age"
    from tbl_dummyfeed t1 join tbl_dummyfeed t2 on t1.payment_id= t2.payment_id
    where t1.event = 'accepted' and t2.event = 'enriched';

当我将转换添加到 hh24:mm:ss 时，解决方案如下所示

SELECT to_char(to_date(max(CASE WHEN t1.time_event < SYSDATE and t2.time_event > SYSDATE THEN round((SYSDATE - t1.time_event) * 24 * 60
* 60) else 0 END),'sssss'),'hh24:mi:ss') as "current_age" from tbl_dummyfeed t1 join tbl_dummyfeed t2 on t1.trax_Id = t2.trax_id where t1.event = 'accepted' and t2.event = 'enriched';

这是我的问题唯一好的解决方案。希望这对人们有所帮助。

Answer 2

您可以使用类似的日期 'trick'，即将小数天差添加到时间部分为午夜的标称日期 - 您可以使用固定日期，或者 trunc(sysdate)，只要时间结束为午夜 - 无需乘以 24*60*60。（您的 to_date() 解决方案隐含地做同样的事情，有效地将秒数添加到当月第一天的午夜；但这可能更清楚一些）。但您也可以将 case 子句移动到 where 过滤器中

select to_char(date '1970-01-01'
  + nvl(max(sysdate - t1.time_event), 0), 'HH24:MI:SS') as "current_age"
from tbl_dummyfeed t1
join tbl_dummyfeed t2
on t1.trax_id = t2.trax_id
where t1.event = 'accepted'
and t1.time_event < sysdate
and t2.event = 'enriched'
and t2.time_event > sysdate;

您还可以使用分析方法，这样您只需点击 table 一次，子查询将每个 'enriched' 时间与前一个 'accepted' 时间配对ID，然后根据当前时间过滤：

select to_char(date '1970-01-01'
  + nvl(max(sysdate - time_accepted), 0), 'HH24:MI:SS') as "current_age"
from (
  select last_value(case when event = 'accepted' then time_event end ignore nulls)
      over (partition by trax_id order by time_event) as time_accepted,
    case when event = 'enriched' then time_event end as time_enriched
  from tbl_dummyfeed
)
where time_accepted < sysdate
and time_enriched > sysdate;

SQL：结合大小写和数字到日期的转换

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