SQL 中判断列中的值是否为null，为null时候用0来代替

  string strsql = "select itemno,cname,ename,shortname,IntervalInvalid,IntervalCheck,IntervalInceptReceive,IntervalCheckSend,isnull(IntervalInvalid,0)+isnull(IntervalCheck,0)+isnull(IntervalCheckSend,0)+isnull(IntervalInceptReceive,0)as couns from testItem  WHERE  1=1 ";