Mandatory and Sortable Field using UI annotations

Hello Experts,

I have created a basic list view using UI annotations in a similar fashion as below link

https://github.com/SAP-samples/cloud-cap-samples/blob/openSAP-week3-unit2/packages/officesupplies/srv/cat-service.cds

I would like to achieve the following:

1. Make one of the Selection Fields Mandatory

2. Enable Sorting on the columns ( when the user clicks on column, the table will sort in ascending/descending order)

Thanks is advance.

Regards,

Krishna