几种常见复合sql查询语句的linq写法[继续补充中]

1.IN 语句
尝试了很多次，好象linq死活不生成in语句，无奈只能做了下变换

例，要找出"手机大类"以及"手机下属所有子类"的产品 (手机大类的ID为D0C37275-2279-4590-A679-C65A4F28918F) 

select  F_ID,F_Name,F_CLsID  From  T_Product  Where  F_ClsID  in  (
  Select  F_ID  From  T_Class  Where  F_ID = ' D0C37275-2279-4590-A679-C65A4F28918F '   OR  F_ParentIdStr  like   ' %D0C37275-2279-4590-A679-C65A4F28918F% ' )

效果上等效于

Select  P.F_ID,P.F_Name,P.F_ClsID  From  T_Product  As  P  Inner   Join  T_Class  As  C  On  C.F_ID  =  P.F_CLSID  where  
C.F_ID = ' D0C37275-2279-4590-A679-C65A4F28918F '   OR  C.F_ParentIdStr  like   ' %D0C37275-2279-4590-A679-C65A4F28918F% '

或

Select  P.F_ID,P.F_Name,P.F_ClsID  From  T_Product  As  P,T_Class  As  C  where  
P.F_ClSID  =  C.F_ID  And  (
C.F_ID = ' D0C37275-2279-4590-A679-C65A4F28918F '   OR  
C.F_ParentIdStr  like   ' %D0C37275-2279-4590-A679-C65A4F28918F% ' )

linq to sql的等效写法:

var query  =  from p  in  db.T_Products join 
              c  in  db.T_Classes on  p.F_CLSID equals c.F_ID
              where  c.F_ID  ==   new  Guid( " D0C37275-2279-4590-A679-C65A4F28918F " )  ||  c.F_ParentIDStr.Contains( " D0C37275-2279-4590-A679-C65A4F28918F " )
             select  new   { p.F_ID, p.F_Name } ;

或

var query  =  from p  in  db.T_Products
                        from c  in  db.T_Classes
                         where  p.F_CLSID  ==  c.F_ID  &&  (c.F_ID  ==   new  Guid( " D0C37275-2279-4590-A679-C65A4F28918F " )  ||  c.F_ParentIDStr.Contains( " D0C37275-2279-4590-A679-C65A4F28918F " ))
                        select  new   { p.F_ID, p.F_Name } ;