当条件为true时，内部连接进入sql server

Question

I want to do inner join when some condition is true

case  
when (select dbo.fnGetProduct_config('CATEGORY_NAME','',''))='XYZ'  
then inner join product_master t12 on t12.id=t1.product_id  
END  

Answer 1

You can't use a conditional to decide whether or not to join (except with dynamic sql), but you can add the predicate to the join....

...
from table1
inner join product_master t12 on t12.id=t1.product_id and dbo.fnGetProduct_config('CATEGORY_NAME','',''))='XYZ'

Answer 2

SELECT * FROM TABLE1 T1
INNER JOIN TABLE2
 ON (fn(T1.Blahblah)==1 AND /*other conditions*/)