Query Parser Rewrite

[StevenMMortimer]

Rewrite the SOQL XML parsing function to simplify and close known issues. Below is a list of these issues and examples of these issues that now execute properly with the new parser.

For individuals who want to test this fix please re-install RForcecom using the following command:

devtools::install_github('ReportMort/RForcecom', ref='bugfix/query-parser-rewrite')

I would appreciate any help from others in verifying that this works for as many query types as possible.

---

Tested Examples based on Outstanding Issues:
#37, #48

#works with parent-child query that requests fields from each object
query <- "SELECT 
              Id
            , StageName
            , Account.Name 
          FROM Opportunity
          LIMIT 5"
rforcecom.query(session, query)

#works with parent-child query that only requests fields from the parent only
query <- "SELECT 
              Account.Id
            , Account.Name 
          FROM Opportunity
          LIMIT 5"
rforcecom.query(session, query)

#works with grandparent-parent-child query that requests fields from each object
query <- "SELECT 
              Id
            , Name
            , Parent.Id
            , Parent.Name
            , Parent.RecordType.Name
            , Parent.Parent.Id
            , Parent.Parent.Name
            FROM Account 
            WHERE Parent.RecordType.Name in ('Tier1')"
rforcecom.query(session, query)

#41
note that SELECT COUNT() still returns null, but the preferred method would be to supply a field to count and then it will return as expected

# simple count works
query <- "SELECT 
              COUNT(Id) cnt
          FROM Opportunity"
rforcecom.query(session, query)

# count works with multiple fields and aliases for each
query <- "SELECT 
              COUNT(Id) oppy_cnt
            , COUNT(CampaignId) campaign_cnt
          FROM Opportunity"
rforcecom.query(session, query)

# count works with a GROUP BY statement
query <-"SELECT 
              LeadSource
            , COUNT(Name) lead_cnt
         FROM Lead
         GROUP BY LeadSource"
rforcecom.query(session, query)

#45

# works with queries pulling field history information 
query <- "SELECT 
            Id
          , IsDeleted
          , OpportunityId
          , CreatedDate
          , Field
          , OldValue
          , NewValue
          FROM OpportunityFieldHistory 
          WHERE 
                CreatedDate >= 2016-11-01T00:00:00Z 
            AND (Field='StageName' OR Field='Amount')"
rforcecom.query(session, query)

[hiratake55]

Thanks, Merged.