584. Find Customer Referee - Easy
문제
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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.
The query result format is in the following example.
입출력 예
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Example 1:
Input:
Customer table:
+----+------+------------+
| id | name | referee_id |
+----+------+------------+
| 1 | Will | null |
| 2 | Jane | null |
| 3 | Alex | 2 |
| 4 | Bill | null |
| 5 | Zack | 1 |
| 6 | Mark | 2 |
+----+------+------------+
Output:
+------+
| name |
+------+
| Will |
| Jane |
| Bill |
| Zack |
+------+
풀이
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SELECT name
FROM Customer as c
WHERE (c.referee_id IS NULL) OR (c.referee_id != 2)