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.
table name: Customers
Explanation:
We need to find details of all those customers whose referee_id is not equal to 2. It could be anything other than 2. It could be null also.
Solution:
select * from Customers where referee_id is null or referee_id !=2
Output:
SQL Script:
CREATE TABLE [dbo].[Customers](
[id][int] NOT NULL,
[name][varchar](50) NULL,
[referee_id][int] NULL,
CONSTRAINT [PK_Customres1] PRIMARY KEY CLUSTERED
(
[id]
ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO
INSERT [dbo].[Customers] ([id], [name], [referee_id]) VALUES (1, N'Will', NULL)
GO
INSERT [dbo].[Customers] ([id], [name], [referee_id]) VALUES (2, N'Jane', NULL)
GO
INSERT [dbo].[Customers] ([id], [name], [referee_id]) VALUES (3, N'Alex', 2)
GO
INSERT [dbo].[Customers] ([id], [name], [referee_id]) VALUES (4, N'Bill', NULL)
GO
INSERT [dbo].[Customers] ([id], [name], [referee_id]) VALUES (5, N'Zack', 1)
GO
INSERT [dbo].[Customers] ([id], [name], [referee_id]) VALUES (6, N'Mark', 2)
GO