Skip to content

Latest commit

 

History

History
58 lines (45 loc) · 1.5 KB

FindCustomerRefree.md

File metadata and controls

58 lines (45 loc) · 1.5 KB
  • SQL Schema
Create table If Not Exists Customer (id int, name varchar(25), referee_id int)
Truncate table Customer
insert into Customer (id, name, referee_id) values ('1', 'Will', 'None')
insert into Customer (id, name, referee_id) values ('2', 'Jane', 'None')
insert into Customer (id, name, referee_id) values ('3', 'Alex', '2')
insert into Customer (id, name, referee_id) values ('4', 'Bill', 'None')
insert into Customer (id, name, referee_id) values ('5', 'Zack', '1')
insert into Customer (id, name, referee_id) values ('6', 'Mark', '2')

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 not referred by the customer with id = 2.

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

Solution:

select name from Customer where referee_id<>2 or referee_id is null;