sql case when语法

方式一：
select a.orgid,b.orgname,a.tasktime,a.tasktype,case a.taskstatus when '0' then '准备'  when  '1' then '进行中' end as taskstatus
from m_new_taskstatus a,m_branch b
where a.orgid=b.orgid

方式二：
select a.orgid,b.orgname,a.tasktime,a.tasktype,case when a.taskstatus='0' then '准备' else case when  a.taskstatus='1' then '进行中'  else '有效' end end as taskstatus
from m_new_taskstatus a,m_branch b
where a.orgid=b.orgid



这个是ISNULL函数使用
string sql = "select a.orgid,a.brokertype,a.brokerlevel,c.orgname,b.brokername,a.levelname,ISNULL(a.basesalary,0) as basesalary,ISNULL(a.firstrate,0) as firstrate,ISNULL(a.secondrate,0) as secondrate,ISNULL(a.thirdrate,0) as thirdrate,ISNULL(a.quarterscore,0) as quarterscore,ISNULL(a.teamcoef,0) as teamcoef"
            +" from m_new_brokergrade a , m_new_brokertype b, m_branch c "
            + " where a.orgid=c.orgid and a.brokertype=b.brokertype  and a.orgid='" + bto.Orgid + "'  order by a.levelname asc";