sql - 当条件为真时，内部连接进入 sql server

Question

当某些条件为真时，我想进行内部连接

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

Answer 1

您不能使用条件来决定是否加入（动态 sql 除外），但您可以将谓词添加到联接中......

...
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*/)