SFDC - Find related records

related_records.apex

String recid = 'a2W10000001g0tiEAA'; // change this
Schema.DescribeSObjectResult R = SVMXC__Site__c.SObjectType.getDescribe(); // change this
List<Schema.ChildRelationship> C = R.getChildRelationships(); 

String s = '';
String s2 = '';

System.debug('START');

for(Schema.ChildRelationship rel:C) {
    //System.debug('Child Name '+rel.getChildSObject());    
    //System.debug('Field Name '+rel.getField());    
    //System.debug('Rel Name '+rel.getRelationshipName());        

    String r = rel.getRelationshipName();

    if (r != null) {
       s += '(SELECT id FROM ' + rel.getRelationshipName() + ')';

       if (c.indexOf(rel) != c.size()-1) {
           s += ', ';
       }
    }

    s2 = 'SELECT COUNT() FROM ' + rel.getChildSObject() + ' WHERE ' + rel.getField() + ' = \'' + recid + '\'';

    if (rel.getChildSObject().getDescribe().queryable 
       && rel.getChildSObject().getDescribe().searchable
       && (!s2.containsIgnoreCase('FeedItem'))
    ){
       
       Integer num = Database.countQuery(s2);

//       if (num != 0) {
          System.debug(',' + s2 + ',' + recid + ',' + rel.getChildSObject() + ',' + rel.getChildSObject().getDescribe().label + ',' + rel.getField() + ',' + num);
//       }
    }
}

System.debug('END');