WHERE value IS NOT IN (underforespørgsel)

Opdateret: Vi bør bruge foretrækker at bruge joins for bedre ydeevne, når det er nemt at gøre for os. Deltag vs. underforespørgsel

Sql Fiddle

Select distinct Customer from orders o
join 
(
  SELECT distinct Customer as changedname FROM Orders o2 
  join
  (
     Select distinct invoice from Promotions where Coupon='couponA'
  ) t3
  on o2.invoice = t3.invoice      
) t2
on o.customer != t2.changedname;

Bemærk:Jeg har ændret kolonnenavnkunde for t3, fordi to sammenføjede tabeller skal have forskellige kolonnenavne

Forklaring:

Det er dyrt at bruge indre eller underforespørgsler, når du har big data. brug joins i stedet, lad os lære at konvertere underforespørgsel til join

Med Underforespørgsel Vi havde:

Select distinct Customer from orders where customer not in 
(SELECT distinct Customer FROM Orders where invoice in
(Select distinct invoice from Promotions where Coupon='couponA'));

Konverterer underforespørgsel til at deltage

Første trin:

Select distinct Customer from orders o
join 
(
  SELECT distinct Customer as changedname FROM Orders where invoice in
  (Select distinct invoice from Promotions where Coupon='couponA')
) t2
on o.customer != t2.changedname;

2. trin:

Select distinct Customer from orders o
join 
(
  SELECT distinct Customer as changedname FROM Orders o2 where invoice 
  join
  (
     Select distinct invoice from Promotions where Coupon='couponA'
  ) t3
  on o2.invoice = t3.invoice      
) t2
on o.customer != t2.changedname;

Og det er det, meget hurtigere for tabeller med adskillige rækker

Oprindeligt svar:

Brug not in . Tag et kig.

Select distinct Customer from orders where customer not in 
(SELECT distinct Customer FROM Orders where invoice in
(Select distinct invoice from Promotions where Coupon='couponA'));

Rediger Jeg har tilføjet distinkt for at gøre forespørgslen hurtigere

SQL Fiddle