Hi All,

I am trying to insert a list of related records in Apex and found the documentation that explains how to do so for inserting 1 parent and 1 child record. Here is the snippet I am talking about and link for the same:
https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/langCon_apex_dml_foreign_keys.htm

public class ParentChildSample {
    public static void InsertParentChild() {
        Date dt = Date.today();
        dt = dt.addDays(7);
        Opportunity newOpportunity = new Opportunity(
            Name='OpportunityWithAccountInsert',
            StageName='Prospecting',
            CloseDate=dt);
        
        // Create the parent reference.
        // Used only for foreign key reference
        // and doesn't contain any other fields.
        Account accountReference = new Account(
            MyExtID__c='SAP111111');                
        newOpportunity.Account = accountReference;
        
        // Create the Account object to insert.
        // Same as above but has Name field.
        // Used for the insert.
        Account parentAccount = new Account(
            Name='Hallie',
            MyExtID__c='SAP111111');      
        
        // Create the account and the opportunity.
        Database.SaveResult[] results = Database.insert(new SObject[] {
            parentAccount, newOpportunity });
        
        // Check results.
        for (Integer i = 0; i < results.size(); i++) {
            if (results[i].isSuccess()) {
            System.debug('Successfully created ID: '
                  + results[i].getId());
            } else {
            System.debug('Error: could not create sobject '
                  + 'for array element ' + i + '.');
            System.debug('   The error reported was: '
                  + results[i].getErrors()[0].getMessage() + '\n');
            }
        }
    }
}

Now I want to replicate this functionality to insert a List of related records instead of a single record and I get an error when I just change the below line from documentation :

// Create the account and the opportunity.
Database.SaveResult[] results = Database.insert(new SObject[] { parentAccount, newOpportunity });

To:

// Create the account and the opportunity.
Database.SaveResult[] results = Database.insert(new SObject[] { parentAccountLIST, newOpportunityLIST });

Any help on what parameters change for inserting a list will be of great help.

Thank you!!