SQL查詢來獲取其列表不應該與其他表列相匹配的錶行

Question

在此先感謝，

其實我有兩個表購物車和支票。車表包含行如下

id |username |orderid | exam_name | price 
1 | Rajesh | ABC123 | PMP  | $60 
2 | Rajesh | ABC123 | CPM  | $70 
3 | David | ABC789 | ITIL  | $80 

checks表包含行如下

id |username |order_id | exam  | price 
1 Rajesh | ABC123 | PMP  | $60 
2 Rajesh | ABC123 | CPM  | $70 

我需要的車表，它的OrderID列，EXAM_NAME列不應該配合檢查表的order_id列和考試的行數據列

事情是這樣的，如下：

id |username |orderid | exam_name | price 
1 | David | ABC789 | ITIL  | $80 

Answer 1

一種方法是not exists：

select c.* 
from carts c 
where not exists (select 1 
        from checks ch 
        where ch.orderid = c.orderid and ch.exam_name = c.exam_name 
       ); 

類似的方法是left join：

select c.* 
from carts c left join 
    checks ch 
    on ch.orderid = c.orderid and ch.exam_name = c.exam_name 
where ch.orderid is null; 

而且在某些數據庫可以使用not in：

select c.* 
from carts c 
where (c.orderid, c.exam_name) not in (select ch.orderid, ch.exam_name from checks ch); 

Answer 2

select c.* 
from carts c 
left join checks ch on c.id = ch.id 
where ch.id is null; 

希望這應該解決你的問題。

Answer 3

SELECT * 
from Carts 
where exam_name not in (select exam  from checks) 
and id not in (select id from checks) 

Answer 4

SELECT * FROM Carts 
WHERE NOT EXISTS (SELECT 1 FROM checks 
    WHERE checks.OrderId = Carts.OrderId 
    and Carts.exam_name = checks.exam_name)