基于Teradata中的条件优先级填充列

我需要根据条件优先级填充列：

如果

O_M

不是零（例如：

0.34

），我检查

Prev。将

（按

TP_N

排序）记录在同一列

O_M

中，如果使用代码

（OD03，OT03，MO03）

编码的3个或更多实例的值为零，则我应该使用当前的

O_M

值填充

以计算列
。我需要对由
TP\u N
排序的每个分区（
DT，MNTH，P\u ID，A\u BR，D\u BR，B\u BR，DR）重复此操作。我应该只从列
O\u N
-
（OD03、OT03、MO03）

但是，如果
O_M
不是零（例如：
0.6
-列
O_M
从底部算起的第11行），我检查
Prev。记录
在同一列
O_M
中，我只有两个以前的记录作为
zero
（对于使用代码
（OD03，OT03，MO03）编码的3个或更多实例
，那么我应该填充
以使用
0
计算列

如果
O_M
不是零（例如
O_M
的
0.3
最后第三行），我检查同一列
O_M
中的
Prev.record
，在这里用代码
编码的3个或更多实例为零（OD03，OD03，OD03）
然后我应该用当前
O\u M
值填充
以计算
列-
0.3

我是TD新手。对这方面的任何了解都会有所帮助。
未经测试，但根据您的描述，这应该是可行的：

case
   when sum(O_M) -- previous three rows are all 0 (assuming no negative values exist)
        over (partition by ??
              order by TP_N
              rows between 3 preceding and 1 preceding) = 0
    and -- prvious three rows contain any of the searched codes
        sum(case when O_N IN ('OD03','OT03','MO03') then 1 else 0 end)
        over (partition by ??
              order by TP_N
              rows between 3 preceding and 1 preceding) = 3
   then O_M
   else 0
end

我将为您提供两种可能的解决方案，以决定哪种方案最适合您的情况。第一种方案更简单，但更繁琐，因为它只会连接到同一个表3次。假设上面的数据存在于DATASET表中：

select ds1.dt
,ds1.mnth
,ds1.p_id
,ds1.a_br
,ds1.d_br
,ds1.b_br
,ds1.tp_n
,ds1.dr
,ds1.o_m
,ds1.o_n
,case when zeroifnull(ds4.o_m) + zeroifnull(ds3.o_m) + zeroifnull(ds2.o_m) = 0 and ds4.o_n in ('OD03','OT03','MO03') and ds3.o_n in ('OD03','OT03','MO03') and ds2.o_n in ('OD03','OT03','MO03') then ds1.o_m
else 0 end as TO_COMPUTE
from dataset ds1
left join dataset ds2
on ds1.tp_n = ds2.tp_n +1
and ds1.dt = ds2.dt
and ds1.mnth = ds2.mnth
and ds1.p_id = ds2.p_id
and ds1.a_br = ds2.a_br
and ds1.d_br = ds2.d_br
and ds1.b_br = ds2.b_br
and ds1.dr = ds2.dr
left join dataset ds3
on ds1.tp_n = ds3.tp_n +2
and ds1.dt = ds3.dt
and ds1.mnth = ds3.mnth
and ds1.p_id = ds3.p_id
and ds1.a_br = ds3.a_br
and ds1.d_br = ds3.d_br
and ds1.b_br = ds3.b_br
and ds1.dr = ds3.dr
left join dataset ds4
on ds1.tp_n = ds4.tp_n +3
and ds1.dt = ds4.dt
and ds1.mnth = ds4.mnth
and ds1.p_id = ds4.p_id
and ds1.a_br = ds4.a_br
and ds1.d_br = ds4.d_br
and ds1.b_br = ds4.b_br
and ds1.dr = ds4.dr
order by 7;

第二个使用子查询中的分区：

select sub.dt
,sub.mnth
,sub.p_id
,sub.a_br
,sub.d_br
,sub.b_br
,sub.tp_n
,sub.dr
,sub.o_m
,sub.o_n
,case when o_m2 = 0 and o_m3 = 0 and o_m4 = 0 and o_n2 in ('OD03','OT03','MO03') and o_n4 in ('OD03','OT03','MO03') and o_n4 in ('OD03','OT03','MO03') then sub.o_m
else 0 end as TO_COMPUTE
from
(
select ds.dt
,ds.mnth
,ds.p_id
,ds.a_br
,ds.d_br
,ds.b_br
,ds.tp_n
,ds.dr
,ds.o_m
,ds.o_n
,max(ds.o_m) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 1 preceding and 1 preceding) as O_M2
,max(ds.o_m) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 2 preceding and 2 preceding) as O_M3
,max(ds.o_m) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 3 preceding and 3 preceding) as O_M4
,max(ds.o_n) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 1 preceding and 1 preceding) as O_N2
,max(ds.o_n) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 2 preceding and 2 preceding) as O_N3
,max(ds.o_n) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 3 preceding and 3 preceding) as O_N4
from dataset ds
) sub
order by 7;

列O_N中的代码是否必须按特定顺序排列，并且所有三个都必须存在？如果3个或更多上一个连续记录为零，则我检查O_N列，它必须在这三个代码内。（无空）。无特定顺序。根据我的经验，您不能在“when”中使用窗口函数是案例陈述的一部分，但你可以在“then”部分使用。@M.Wise：当你可以在中使用它时，你也可以在When或ELSE中使用它：-）我昨天确认过。您在WHEN中出现“非法使用Case”错误，而在WHEN中运行良好。@M.Wise:嗯，我一直都在这样做，这一定是其他原因。您能分享失败的部分吗？@dnoeth工作得很好。我正在检查场景。然而，对于发布的问题，我得到了预期的结果
select sub.dt
,sub.mnth
,sub.p_id
,sub.a_br
,sub.d_br
,sub.b_br
,sub.tp_n
,sub.dr
,sub.o_m
,sub.o_n
,case when o_m2 = 0 and o_m3 = 0 and o_m4 = 0 and o_n2 in ('OD03','OT03','MO03') and o_n4 in ('OD03','OT03','MO03') and o_n4 in ('OD03','OT03','MO03') then sub.o_m
else 0 end as TO_COMPUTE
from
(
select ds.dt
,ds.mnth
,ds.p_id
,ds.a_br
,ds.d_br
,ds.b_br
,ds.tp_n
,ds.dr
,ds.o_m
,ds.o_n
,max(ds.o_m) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 1 preceding and 1 preceding) as O_M2
,max(ds.o_m) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 2 preceding and 2 preceding) as O_M3
,max(ds.o_m) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 3 preceding and 3 preceding) as O_M4
,max(ds.o_n) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 1 preceding and 1 preceding) as O_N2
,max(ds.o_n) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 2 preceding and 2 preceding) as O_N3
,max(ds.o_n) over (partition by ds.dt, ds.mnth, ds.p_id, ds.a_br, ds.d_br, ds.b_br, ds.dr order by ds.tp_n rows between 3 preceding and 3 preceding) as O_N4
from dataset ds
) sub
order by 7;