SQL: … WHERE X IN (SELECT Y FROM …)

Question

Is the following the most efficient in SQL to achieve its result:

SELECT * 
  FROM Customers 
 WHERE Customer_ID NOT IN (SELECT Cust_ID FROM SUBSCRIBERS)
         


        

Answer 1

Maybe try this

Select cust.*

From dbo.Customers cust
Left Join dbo.Subscribers subs on cust.Customer_ID = subs.Customer_ID
Where subs.Customer_Id Is Null