select
(c.datefield) as dfield,
(select
    count(t1.C_URI)
    from
        (select C_URI,MAX(C_updated) dataOpen from  workitem wi where C_status<>'closed' and date(C_updated)<=c.datefield group by C_URI) t1
    left outer join
        (select C_URI,MAX(C_updated) dataClosed from  workitem wi where C_status='closed' and date(C_updated)<=c.datefield group by C_URI) t2
    on
        t1.C_URI=t2.C_URI
    where
        t1.dataOpen> ifnull(t2.dataClosed,0)
) as tot
from
    calendar c
left join
    workitem
on
    date(datefield)=date(C_updated)
where
    datefield between ('2014-10-01') and ('2014-10-20')
group by
    datefield;

Error Code: 1054. Unknown column 'calendar.datefield' in 'where clause' 0.000 sec