在ABAP CDS视图中将DATS转换为字符串

Question

我有一个简单的CDS视图。执行它时，出现错误invalid format (return table) row number 1 property name。

我认为我需要将日期转换为字符串或char类型，但是存在此语法错误：

  

CHAR类型上的CAST DOGUM_TARIHI：目标类型的长度信息丢失

这是我的代码：

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

为上帝的缘故，请添加以下长度信息：

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

但是，这只会按原样转换日期，而不会使其可读：

20190822 -> 20190822

如果要根据DD.MM.YYYY格式使其可读，则使其如下：

@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';

这将从 20190822 起设置为 2019年8月22日。