Count records in Query Vs Cound Loops in Query

Sometime we do need to know the number of records fetching through X++ query and this can be achieved by 

SysQuery::CountRecords(QueryRun) function. 

This function works similar to this X++ logic;

ProjTable   projTable;    

select count(RecId) from projTable;info(strFmt("%1 total records", projTable.RecId)); // total tecords 1130

Lets see with X++ query;

static void CountProjTableRecords(Args _args)

{      

    Query                           query = new Query();    

    QueryRun                     queryRun;    

    QueryBuildDataSource qbd;    
    qbd = query.addDataSource(tablenum(ProjTable));   
    queryRun = new QueryRun(query);   
    info(strfmt("Total Records in Query %1", SysQuery::countTotal(queryRun))); // total tecords 1130

}

However, this SysQuery::CountRecords(QueryRun) function count only the number of records of the first datasource.

 Let's assume if we need to count number of records of a query with more than one datasource, 

we need to use SysQuery::CountLoops(QueryRun) function.

static void CountProjTableRecords(Args _args)

{      

    Query                           query = new Query();    

    QueryRun                     queryRun;    

    QueryBuildDataSource qbds, qbds1;    
    qbds = query.addDataSource(tablenum(ProjTable));    

    qbds1 = query.addDataSource(tablenum(ProjTable)).addDataSource(tablenum(ProjForecastTable));    
    queryRun = new QueryRun(query); 
    info(strfmt("Total Records in Query %1", SysQuery::countLoops(queryRun))); 

}