Skip to content

584. Find Customer Referee

Database

Problem - Find Customer Referee

Easy

Table: Customer

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| name        | varchar |
| referee_id  | int     |
+-------------+---------+
In SQL, 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.

 

Find the names of the customer that are either:

  1. referred by any customer with id != 2.
  2. not referred by any customer.

Return the result table in any order.

The result format is in the following example.

 

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 |
+------+

Solutions

1
2
3
SELECT name
FROM Customer
WHERE referee_id != 2 or referee_id is NULL

Submission Stats:

  • Runtime: 422 ms (93.79%)
  • Memory: 0.0B (100.00%)