在oracle中获取最大值MON-YYYY的完整日期值

Question

我附上一张图片作为我的样本数据，我想要做的是获取trans_date的最大月份和年份，并获得其flow_amt的总和。

示例输出

AF935906 | 22335.86 | DEC-17

这是我的上一次查询，但输出错误

select ltd.acid, sum(ltd.flow_amt) sum_flow_amt, MAX(to_char(ltd.tran_date, 'Mon-YYYY')) as transac_date
    from tbaadm.ltd ltd
    where
      ltd.tran_date <= '31-DEC-17' and ltd.acid = 'AF935906'

由于

Answer 1

您正在将MAX应用于字符串（TO_CHAR(...)。因此，比较是字母的，'Jan-2001'大于'Dec-2017'，因为'D'出现在'J'之前字母表。

因此请在日期使用MAX，然后才应用格式函数TO_CHAR。

select 
  ltd.acid, 
  sum(ltd.flow_amt) as sum_flow_amt, 
  to_char(max(ltd.tran_date), 'Mon-YYYY') as transac_date
from tbaadm.ltd ltd
where ltd.tran_date <= date '2017-12-31' and ltd.acid = 'AF935906'
group by ltd.acid;

更新：您说您只想要上个月的总和。因此，将Oracle的KEEP LAST子句添加到SUM。

select 
  ltd.acid, 
  sum(ltd.flow_amt) keep (dense_rank last order by trunc(tran_date, 'month')) as sum_flow_amt, 
  to_char(max(ltd.tran_date), 'Mon-YYYY') as transac_date
from tbaadm.ltd ltd
where ltd.tran_date <= date '2017-12-31' and ltd.acid = 'AF935906'
group by ltd.acid;

Answer 2

我想你想要更像这样的东西：

select acid, yyyymm, sum_flow_amt
from (select ltd.acid, to_char(ltd.tran_date, 'YYYY-MM') as yyyymm,
             max(tran_date) as max_tran_date,
             sum(ltd.flow_amt) as sum_flow_amt,
             row_number() over (partition by ltd.acid order by to_char(ltd.tran_date, 'YYYY-MM') desc) as seqnum
      from tbaadm.ltd ltd
      where ltd.tran_date <= date '2017-12-31' and ltd.acid = 'AF935906'
      group by ltd.acid, to_char(ltd.tran_date, 'YYYY-MM')
     ) ad
where seqnum = 1;

我更喜欢以YYYY-MM格式输出。如果您真的想要其他格式的日期，请使用：

select acid, to_char(max_tran_date, 'MMM-YYYY') as mmmyyyy, sum_flow_amt