Restful ABAP CDS metadata extension columns

[AJeB]

HI I have two CDS view that get records from VBAK and LIPS

the requirement is to get the Sales Order with Delivery and display the delivery in the column

this is the CDS of LIPS

in VBAK CDS I got a warning message -> The association _ZI_AJ_SD_LIPS2 can modify the cardinality of the results set

After displaying it in FIORI list report it is displaying 2 same Sales Order and it has same records

How can I prevent the duplicate records, I already tried to add DISTINCT keyword but its not working? 

[junwu]

show us your vbak cds.

[raymond_giuseppi]

You have used LIPS, i.e. the delivery lines and not the headers. There are no duplicates if you included the item number in the delivery (lips-posnr), hence the failure of DISTINCT.

Could you provide description of _ZI_AJ_SD_VBAK2 and _ZI_AJ_SD_LIPS2 in text, not pictures.