Database.SaveResult[] saveResultList = Database.insert(insertList, false);

​

// Iterate through saveResultList based on isSuccess capture the failed records

for (Database.SaveResult sr : saveResultList) {

    if (sr.isSuccess()) {

        // Operation was successful, so get the ID of the record that was processed

        System.debug('Successfully inserted account. Account ID: ' + sr.getId());

    }

    else {

        // Operation failed, so get all errors                

        for(Database.Error err : sr.getErrors()) {

            System.debug('The following error has occurred.');                    

            System.debug(err.getStatusCode() + ': ' + err.getMessage());

            System.debug('Account fields that affected this error: ' + err.getFields());

        }

    }

}