Sql语句查询问题?
有两张表,act_type和act_nextType里存的都是type_id值,我想查询出对应的名称,应该怎么写?

CREATE   TABLE   [dbo].[t_Activity]   (
[Act_ID]   [int]   IDENTITY   (1,   1)   NOT   NULL   ,
[Act_Type]   [int]   NULL   ,
[Act_NextType]   [int]   NULL   )   ON   [PRIMARY]
GO

CREATE   TABLE   [dbo].[t_ActivityType]   (
[Type_ID]   [int]   IDENTITY   (1,   1)   NOT   NULL   ,
[Type_Name]   [nvarchar]   (50)   COLLATE   Chinese_PRC_CI_AS   NULL  
)   ON   [PRIMARY]
GO

请指点,谢谢!

------解决方案--------------------
select Type_Name,t_Activity.*
from
t_ActivityType inner join t_Activity on t_ActivityType.Type_ID=t_Activity.Act_Type
------解决方案--------------------
select t_Activity.*,(select type_name from t_activitytype where type_id=t_Activity.Act_type) as act_typename,(select type_name from t_activitytype where type_id=t_Activity.Act_nexttype) as act_nextypename from t_activity
------解决方案--------------------
select Type_Name from t_ActivityType where Type_ID=?
输出 id--name