有关sql语句急!!! select a.nrfl, letterProcessed, letterProcessing from (select nrfl, count(docid) as letterProcessed from wsxf_document where status != 4and create_Date >='2011-11-11 00:00:00' and create_date <= '2011-12-01 23:59:59'group by nrfl) a full outer join (select nrfl, count(docid) as letterProcessing from wsxf_document where status = 4 and create_Date >='2011-11-11 00:00:00' and create_date <= '2011-12-01 23:59:59' group by nrfl) b on a.nrfl = b.nrfl