MySQL - count rows per hour

In this article, we would like to show you how to count rows per hour in MySQL.

Quick solution:

SELECT COUNT(*), HOUR(`timestamp_column_name`)
FROM `table_name`
GROUP BY HOUR(`timestamp_column_name`);

Note:

This solution works both for TIMESTAMP and DATETIME type.

Practical example

To show how to count rows per hour, we will use the following table:

Note:

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

Example

In this example, we will display the date and the number of registered users for each hour.

Query:

SELECT
    HOUR(`registration_time`) AS 'hour',
	COUNT(*) AS 'number_of_times'
FROM `users`
GROUP BY HOUR(`registration_time`);

Result:

Database preparation

create_tables.sql file:

CREATE TABLE `users` (
	`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
	`username` VARCHAR(50) NOT NULL,
	`registration_time` DATETIME NOT NULL,
	PRIMARY KEY (`id`)
);

insert_data.sql file:

INSERT INTO `users`
	(`username`, `registration_time`)
VALUES
	('Tom', '2021-01-01 11:41:31'),
	('Chris','2021-01-02 11:42:45'),
	('Jack','2021-01-03 15:13:39'),
    ('Kim','2021-01-03 15:24:51'),
    ('Marco','2021-01-04 22:35:38'),
	('Kate','2021-01-04 22:46:51'),
	('Nam','2021-01-04 22:57:37');