HI ZigZag,
Thanks for choosing Syncfusion products.
You can achieve your requirement by setting HideEmptyChildGrid property as True in the GridDataControl. This is working fine for the Collection of objects however we are able to find that, this property does not work while binding DataTable to the GridDataControl. We have fixed this issue internally and we request you to create an Incident in our Direct Trac Support System by using the below link to get patch for this fix.
https://www.syncfusion.com/account/login?ReturnUrl=%2fsupport%2fdirecttrac%2fincidents Please let us know if you have any queries.
Thanks,
Rajasekar