Add Custom SObject to List of SObjects in Apex Controller - salesforce

Question

I have a custom Apex controller where I have an SOQL query that gets a count of all objects that have a certain status and that are children of another object. The query is:
List<SObject> statuses = [SELECT Status__c, COUNT(Id) statusCount FROM Application__c WHERE CERT__c = :certId GROUP BY Status__c];
Status__c is a Picklist. I also have code to get all of the possible values of the Picklist.
What I want to do is if statuses does not contain any entries that have a specific Status__c value, to add the value name with a count of 0. For some reason when I try to create a new SObject with a Status__c and Count, it doesn't seem to like it. Is there a way to add a custom SObject to the list? Or, should I be handling this differently?

Answer 1

I was very surprised that your query works. Result of queries with GROUP BY is AggregateResult, I didn't know it can be cast down to sObject. Maybe initial success with this made you fail in the next steps...
Something like this should point you in right direction:
Map<String, Integer> results = new Map<String, Integer>();
for(Schema.PicklistEntry pe : Lead.LeadSource.getDescribe().getPicklistValues()){
results.put(pe.getValue(), 0);
}
System.debug('Before: ' + JSON.serializePretty(results));
for(AggregateResult ar : [SELECT LeadSource, COUNT(Id) cnt FROM Lead WHERE LeadSource != null GROUP BY LeadSource]){
results.put((String) ar.get('LeadSource'), (Integer) ar.get('cnt'));
}
System.debug('After: ' + JSON.serializePretty(results));
Before: {
"Some more types" : 0,
"Hi Stackoverflow!" : 0,
"Other" : 0,
"Purchased List" : 0,
"Partner Referral" : 0,
"Phone Inquiry" : 0,
"Web" : 0
}
After: {
"Some more types" : 0,
"Hi Stackoverflow!" : 0,
"Other" : 0,
"Purchased List" : 7,
"Partner Referral" : 4,
"Phone Inquiry" : 4,
"Web" : 7
}