DataBase -- Customers Who Never Order
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Question:
Suppose that a website contains two tables, the Customers table and the Orders table. Write a SQL query to find all customers who never order anything.
Table: Customers.
+----+-------+ | Id | Name | +----+-------+ | 1 | Joe | | 2 | Henry | | 3 | Sam | | 4 | Max | +----+-------+
Table: Orders.
+----+------------+ | Id | CustomerId | +----+------------+ | 1 | 3 | | 2 | 1 | +----+------------+
Using the above tables as example, return the following:
+-----------+ | Customers | +-----------+ | Henry | | Max | +-----------+
Analysis:
写一个SQL语句，找出没有被order的顾客。
Answer：
select Name from Customers where Id not in (select CustomerId from Orders);
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