MS SQL Server - count duplicated rows

In this article, we would like to show you how to count duplicated rows in MS SQL Server.

Quick solution:

SELECT 
    [column_name], COUNT([column_name])
FROM
    [table_name]
GROUP BY 
    [column_name]
HAVING 
    (COUNT([column_name]) > 1);

Practical example

To show how to count duplicated rows, we will use the following users table:

Note:

At the end of this article you can find database preparation SQL queries.

Example

In this example, we will count duplicated user names.

Query:

SELECT 
    [name], COUNT([name]) AS 'count'
FROM
    [users]
GROUP BY 
    [name]
HAVING 
    (COUNT([name]) > 1);

Result:

Database preparation

create_tables.sql file:

CREATE TABLE [users] (
	[id] INT IDENTITY(1,1),
	[name] VARCHAR(100) NOT NULL,
	[email] VARCHAR(100) NOT NULL,
	[country] VARCHAR(15) NOT NULL,
	PRIMARY KEY ([id])
);

insert_data.sql file:

INSERT INTO [users]
	([name], [email], [country])
VALUES
	('Tom', 'tom1@email.com', 'Poland'),
	('Tom', 'tom2@email.com', 'Poland'),
    ('Tom', 'tom3@email.com', 'Poland'),
    ('Kim', 'kim1@email.com', 'Vietnam'),
    ('Kim', 'kim2@email.com', 'Vietnam'),
    ('Chris', 'chris1@email.com', 'Spain'),
	('Chris', 'chris2@email.com', 'Spain'),
	('Chris', 'chris3@email.com', 'USA');