[Leetcode] [SQL] Customers who never Order

https://leetcode.com/problems/customers-who-never-order/

Customers who never Order

Suppose that a website contains the table and the table tables Customers Orders . Write a SQL query to find all customers The 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       |+-----------+

Long time no write SQL Suddenly forget is null this thing, = null is not used.

Select  as  from  Left Join  on = where  is NULL

[Leetcode] [SQL] Customers who never Order