从另一个 Case 语句引用 Case 语句中的标识符

Question

所以我有一个看起来像这样的案例陈述：（编辑的实际报告代码）

select
     case
        when t1.reportcode in ('x', 'y', 'z') then 'AFMC'
        when t2.reportcode in ('x', 'y', 'z') then 'AFMC'
        when t1.reportcode in ('x', 'y', 'z') then 'FOH'
        when t2.reportcode in ('x', 'y', 'z') then 'FOH'
        when t1.reportcode in ('x', 'y', 'z') then 'Forest Service'
        when t2.reportcode in ('x', 'y', 'z') then 'Forest Service'
        when t1.reportcode in ('x', 'y', 'z') then 'HHS-Strive'
        when t2.reportcode in ('x', 'y', 'z') then 'HHS-Strive'
        when t1.reportcode in ('x', 'y', 'z') then 'NASA'
        when t2.reportcode in ('x', 'y', 'z') then 'NASA'
        when t1.reportcode in ('x', 'y', 'z') then 'VA SLC'
        when t2.reportcode in ('x', 'y', 'z') then 'VA SLC'
        when t1.reportcode in ('x', 'y', 'z') then 'ABMC'
        when t2.reportcode in ('x', 'y', 'z') then 'ABMC'
        when t1.reportcode in ('x', 'y', 'z') then 'DFAS'
        when t2.reportcode in ('x', 'y', 'z') then 'DFAS'
        when t1.reportcode in ('x', 'y', 'z') then 'DON'
        when t2.reportcode in ('x', 'y', 'z') then 'DON'
     end as FirstGroups,

它会检查所有这些代码并在代码匹配时为其提供一个标识符（ABMC、AFMC 等）。

在此之后，我有另一个看起来像这样的 case 语句：

case
        when 'ABMC' not in FirstGroups then 'ABMC N/A'
        when 'AFMC' not in FirstGroups then 'AFMC N/A'
        when 'DFAS' not in FirstGroups then 'DFAS N/A'
        when 'DON' not in FirstGroups then 'DON N/A'
        when 'FOH' not in FirstGroups then 'FOH N/A'
        when 'Forest Service' not in FirstGroups then 'Forest Service N/A'
        when 'HHS-Strive' not in FirstGroups then 'HHS-Strive N/A'
        when 'NASA' not in FirstGroups then 'NASA N/A'
        when 'VA SLC' not in FirstGroups then 'VA SLC N/A'
 end as NotApplicable,

这里的目标是查看我从第一个 case 语句中得到的输出，如果其中一个标识符（如“VA SLC”或“ABMC”不在其中，那么它会将它在自己的列中显示“VA SLC N/A”、“ABMC N/A”等...不幸的是，我无法在第二个案例语句的第一个案例语句中引用该 FirstGroups 标识符。我也尝试过使用 t1.reportcode 和 t2.reportcode，但这些都不起作用。

预期的输出如下所示：

FirstGroups            NotApplicable
ABMC                   AFMC N/A
DFAS                   NASA N/A
DON
FOH
Forest Service
NASA
VA SLC

或类似的东西。

如果您对我如何做到这一点有任何想法，请告诉我。谢谢！

Answer 1

not in FirstGroups 建议您尝试将该列中的所有值视为一个集合，并从所有组的列表中排除该集合的成员以形成第二列；这与同一行的第一列中的值无关。您的示例输出似乎支持这一点。

这似乎是客户端应该处理的事情 - 您查询以获取第一组，并知道（或单独查询）所有组的列表，并让客户端适当地显示。

你可以用 SQL 来做，只是有点乱，尤其是不能使用 CTE。

这使用了两个内联视图；第一个获取您已经拥有的firstgroups 值，尽管我根据您的预期输出添加了一个不同的值；第二个通过使用您的固定组名列表并排除firstgroups 中的组名来获取不适用的值。不幸的是，因为您不能使用 CTE，这意味着重复您的原始案例陈述来进行排除。

这些内联视图中的每一个都添加了一个分析排名列，因此您示例中的 firstgroups 获得排名 1-7 的行，第二个获得排名 1-2 的行。

这两个内联视图然后以该等级作为连接条件进行外部连接。

select fg.groupname as firstgroups, na.notapplicable
from (
  select groupname, dense_rank() over (order by groupname) as rnk
  from (
    select distinct case
        when t1.reportcode in (1, 2, 3) then 'AFMC'
        when t1.reportcode in (4, 5, 6) then 'FOH'
        when t1.reportcode in (7, 8, 9) then 'Forest Service'
        when t1.reportcode in (10, 11, 12) then 'HHS-Strive'
        when t1.reportcode in (13, 14, 15) then 'NASA'
        when t1.reportcode in (16, 17, 18) then 'VA SLC'
        when t1.reportcode in (19, 20, 21) then 'ABMC'
        when t1.reportcode in (22, 23, 24) then 'DFAS'
        when t1.reportcode in (25, 26, 27) then 'DON'
      end as groupname
    from t1
  )
) fg
full outer join (
  select column_value || ' N/A' as notapplicable,
    dense_rank() over (order by column_value) as rnk
  from table(sys.odcivarchar2list('ABMC', 'AFMC', 'DFAS', 'DON', 'FOH',
    'Forest Service', 'HHS-Strive', 'NASA', 'VA SLC')
  ) allgroups
  where not exists (
    select 1
    from (
      select case
        when t1.reportcode in (1, 2, 3) then 'AFMC'
        when t1.reportcode in (4, 5, 6) then 'FOH'
        when t1.reportcode in (7, 8, 9) then 'Forest Service'
        when t1.reportcode in (10, 11, 12) then 'HHS-Strive'
        when t1.reportcode in (13, 14, 15) then 'NASA'
        when t1.reportcode in (16, 17, 18) then 'VA SLC'
        when t1.reportcode in (19, 20, 21) then 'ABMC'
        when t1.reportcode in (22, 23, 24) then 'DFAS'
        when t1.reportcode in (25, 26, 27) then 'DON'
      end as groupname
      from t1
    ) firstgroups
    where firstgroups.groupname = allgroups.column_value
  )
) na
on na.rnk = fg.rnk
order by coalesce(fg.rnk, na.rnk);

得到：

FIRSTGROUPS          NOTAPPLICABLE      
-------------------- --------------------
ABMC                 AFMC N/A            
DFAS                 NASA N/A            
DON                                      
FOH                                      
Forest Service                           
HHS-Strive                               
VA SLC                                                            

SQL Fiddle demo。我已经编写了报告代码值来匹配您显示的内容。

使用 CTE 会短一些：

with firstgroups as (
  select groupname, dense_rank() over (order by groupname) as rnk
  from (
    select distinct case
        when t1.reportcode in (1, 2, 3) then 'AFMC'
        when t1.reportcode in (4, 5, 6) then 'FOH'
        when t1.reportcode in (7, 8, 9) then 'Forest Service'
        when t1.reportcode in (10, 11, 12) then 'HHS-Strive'
        when t1.reportcode in (13, 14, 15) then 'NASA'
        when t1.reportcode in (16, 17, 18) then 'VA SLC'
        when t1.reportcode in (19, 20, 21) then 'ABMC'
        when t1.reportcode in (22, 23, 24) then 'DFAS'
        when t1.reportcode in (25, 26, 27) then 'DON'
      end as groupname
    from t1
  )
)
select fg.groupname as firstgroups, na.notapplicable
from firstgroups fg
full outer join (
  select column_value || ' N/A' as notapplicable,
    dense_rank() over (order by column_value) as rnk
  from table(sys.odcivarchar2list('ABMC', 'AFMC', 'DFAS', 'DON', 'FOH',
    'Forest Service', 'HHS-Strive', 'NASA', 'VA SLC')
  ) allgroups
  where not exists (
    select 1
    from firstgroups
    where firstgroups.groupname = allgroups.column_value
  )
) na
on na.rnk = fg.rnk
order by coalesce(fg.rnk, na.rnk);

SQL Fiddle demo 获取信息，因为您似乎不适合在您的 SSIS 版本中使用此语法。