DATS to string conversion in ABAP CDS view

Question

I have a simple CDS view. When I execute it, I have the error invalid format (return table) row number 1 property name.

I think I need to cast the date to string or char type, but there's this syntax error:

CAST DOGUM_TARIHI on type CHAR: Length information of target type is missing

Here is my code:

define view ZUMBS_CDS008
as select from zumhr_ddl001 as hr  {
    personel_numarasi,
    personel_adi,
    cast(dogum_tarihi as abap.char) as te33     //<== error at this line
} group by personel_numarasi,personel_adi,dogum_tarihi

Answer 1

So add this length information for the God's sake:

cast(dogum_tarihi as abap.char(8)) as te33 

However, this only converts date as-is, without making it readable:

20190822 -> 20190822

If you want to make it readable according to format DD.MM.YYYY, make it like this:

@AbapCatalog.sqlViewName: 'zcds_sql_usr02'
@EndUserText.label: 'test CDS view'
define view zcds_usr02 as select from usr02 
{
    usr02.bname,
    usr02.gltgb,
    cast(usr02.gltgb as abap.char(10)) as casted,
    concat(
     concat(substring( usr02.gltgb, 7, 2 ), '.'), 
     concat(substring( usr02.gltgb, 5, 2 ), concat('.', substring( usr02.gltgb, 1, 4 )))
     ) as readable
}
where usr02.gltgb <> '00000000';

This will make from 20190822 a date of 22.08.2019.