in 与exists？该怎么解决

in 与exists？？？？

select article ,dealer,price 

from shop  

where article=0001 

or dealer IN (select dealer from shop where article=0001);

装换成exists？？怎么结果不对，谁能帮弄下。

select article ,dealer,price 

from shop  

where 

article=0001 

or

 exists (select dealer from shop where 

shop.dealer=shop.dealer and

 article=0001 );

SQL code

SELECT article ,dealer,price  
FROM shop   
WHERE   
article=0001  
or
EXISTS(SELECT dealer FROM shop WHERE  article=0001 );