Not able to insert Parent Record and child record in the same Apex function

Question

I have a function that have 2 List of Objects in parameters (Schedule__c recList and scheduleTable__c recList2). Once I insert the recList, I am looping through the ID and insert child records to it. To do so, I am doing two loops. Here it is.

@AuraEnabled
public static void saveRecord(List<Schedule__c> recList, List<scheduleTable__c> recList2){
        
    insert recList;

    for(Schedule__c a : recList){
        String newId = a.Id;
        for(scheduleTable__c s : recList2){
            s.Schedule__c.add(newId);
            insert s;
        }
    }
}

I have an error saying Method does not exist or incorrect signature: void add(String) from the type Id. Not too sure what that means... Any idea how I can insert the child record under the Parent record? Thanks

Answer 1

You're calling add on a String/Id, which isn't a valid method (that's what the error means). You probably want to assign each Schedule__c to the related scheduleTable__c, so you need one loop, not two:

insert recList;
for(Integer i = 0, s = recList.size(); i < s; i++) {
    Schedule__c sc = recList[i];
    scheduleTable__c st = recList2[i];
    st.Schedule = sc.Id;
}
insert recList2;

Remember to perform your DML operations outside of a loop, or you'll quickly run up against governor limits.