584. Find Customer Referee
Đề Bài
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.
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 | +------+
Lời Giải
SQL
0584-find-customer-referee.sql
/* Write your T-SQL query statement below */
SELECT name FROM Customer
WHERE referee_id IS NULL OR referee_id != 2