Reuse of Calculated Columns in CDS-View

[ibarbaric]

Hi Experts,

In thread Reuse of Calculated Columns in CDS View, a solution was posted:

select 
  vbeln,
  netwr,
  mwsbk,
  netwr + mwsbk as total,
  ( netwr + mwsbk ) * 1000 as total1000
from vbrk

Note that there is redundancy here: the expression "netwr + mwsbk" occurs twice. This is OK for such a simple case. However, my calculated fields are much more complex and I would like to reuse existing expressions (already created calculated fields), as:

select 
  vbeln,
  netwr,
  mwsbk,
  netwr + mwsbk as total,
  total * 1000 as total1000
from vbrk

I tried:

1. Exactly as above: I got error message "The column 'total' is unknown"
2. With prefix $projection.total: error message "Reuse of $projection expression not possible"
3. I created a second CDS View which reads from the first one, and then I reused the second as association in the first one. I got error message "Recursive definitions are not supported" (which makes sense)

Are there any ideas?
Thanks!
Igor

[ibarbaric]

Hi,
I found a workaround (or if you want to call it "solution"). I am getting used to AI - should have tried before. Anyway, I have got a reply, explaining that what I want is not supported.
The solution / workaround is another CDS-View which nests the first one, as:

define view entity Z_I_Vbrk1 as
select from vbrk
{
  vbeln,
  netwr,
  mwsbk,
  netwr + mwsbk as total,
}

define view entity Z_I_Vbrk2 as
select from Z_I_Vbrk1 as
{
  vbeln,
  netwr,
  mwsbk,
  total,
  total * 1000 as total1000
  // ...further reuse of 'total' 
}

Not that I am happy, because this could mean a complex hierarchy of views, but so far this is the best I could find.

Cheers,

Igor

[ibarbaric]

(how can I delete an accidentally created comment?)