Concatenate 2 list values into single record in apex

Question

List1<account>: ({Name=Acc1, type__c=Marketing,Agree__c=no},{Name=Acc2, type__c=Sales,Agree__c=yes})
List2<account>: ({Name=Acc1, Sla__c=new},{Name=Acc2, Sla__c=pending})

I need to compare list1's name == list2's name and then concatenate/merge two lists into 1 record.

List3<account>: ({Name=Acc1, type__c=Marketing,Agree__c=no,Sla__c=new},{Name=Acc2, type__c=Sales,Agree__c=yes,Sla__c=pending})

Please let me know if it is possible.

Answer 1

As a general rule, you can do that with a Map:

// given list1 and list2 are populated with list of records.
// ObjectType should be Account, Contact, MyCustomObject__c, whatever

Map<String, ObjectType> masterMap = new Map<String, ObjectType>();
for(ObjectType record: list1) {
  masterMap.put(record.Name, new ObjectType());
}
for(ObjectType record: list2) {
  masterMap.put(record.Name, new ObjectType());
}
for(ObjectType record: list1) {
  Map<String, Object> populatedFields = record.getPopulatedFieldsAsMap();
  sObject masterRecord = masterMap.get(record.Name);
  for(String field: populatedFields.keySet()) {
    masterRecord.put(fields, populatedFields.get(field));
  }
}
for(ObjectType record: list2) {
  Map<String, Object> populatedFields = record.getPopulatedFieldsAsMap();
  sObject masterRecord = masterMap.get(record.Name);
  for(String field: populatedFields.keySet()) {
    masterRecord.put(fields, populatedFields.get(field));
  }
}
ObjectType[] list3 = masterMap.values();

The end result is a list of records merged by name with all the values populated. Note that this example has Name as a case-sensitive value (so Demo won't match demo). If you need it to be case insensitive, you'll need to lowercase the key strings so they'll match.