Using Parent-Child Tables with Join

Hi everone..I need Parent Child editing using [https://datatables.net/blog/2019-01-11]

There are two tables : 1) sites[Parent] and 2) users[Child ]

Instead of displaying the total numbers of child rows in parent row, I am in a need to have some mechanism to get the total of a column say Salary of all users(child) of a site. Expanding the parent row should list the individual salary of users alongwith other columns and editing of Salary column must be possible in child rows only. Updating and Deleting of child row(s) be reflected in parent row as a total.

Please help me solve the issue. Thanks