leetcode - 584. Find Customer Referee

난이도 : Easy

 

Table: Customer

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| name        | varchar |
| referee_id  | int     |
+-------------+---------+
id is the primary key column for this table.
Each row of this table indicates the id of a customer, their name, and the id of the customer who referred them.

 

Write an SQL query to report the names of the customer that are not referred by the customer with id = 2.

Return the result table in any order.

 

SELECT name
FROM Customer
WHERE id NOT IN (
                 SELECT id
                 FROM Customer
                 WHERE referee_id = 2
                 )

Accepted (20.90%)

 

 

SELECT name
FROM Customer
WHERE referee_id <> 2
OR referee_id IS NULL

Accepted (13.77%)