get parent id from parentTable to childTable

Question

I have 2 data Table's which having data except parent and child Id, i am fetching schema for these 2 tables from sql while inserting parent table , using Scope Identity ,able to fetch parent  id , but dont know how to add this id to child data table (here child table already have data except id which i have to take from parent table , note : i want to avoid for loop to assign parent id to child table ) how can i achieve this , i am not expecting any code but want some hint do this