SQL如何合并表查询一个表在另一个表中多余的数据

[qq_59728108]

朋友们如果我想从orders表中找出从来没有买过商品的用户，怎么写SQL呢

 

[二月十六]

SELECT * FROM customers LEFT JOIN orders ON customerid=customers.id WHERE customerid IS NULL

[幸福感奇差]

select *
from customers
where not exists (select * from orders
where customers.id = orders.customerid)

[lzhsw]

SELECT NAME FROM CUSTOMERS WHERE ID NOT IN (SELECT CUSTOMERID FROM ORDERS)