select (IFNULL(sum(expend_num),0) - IFNULL(sum(acquire_num),0)) from physic_bill where physic_name=#{name} and physic_spec=#{spec} and batch_no=#{batchNo} and factory_name =#{factoryName}
select (IFNULL(sum(expend_num),0) - IFNULL(sum(acquire_num),0)) from physic_bill where physic_name=#{name} and physic_spec=#{spec} and factory_name =#{factoryName}