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MySQL - count rows with NULL values
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In this article, we would like to show you how to count rows with NULL values in MySQL.
Quick solution:
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SELECT COUNT(*) AS 'alias_name'2
FROM `table_name`3
WHERE `column_name` IS NULL;To show you how to count rows with NULL values, we will use the following users table:
Note:
At the end of this article you can find database preparation SQL queries.
In this example, we will count the number of rows with NULL values in department_id column.
Query
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SELECT COUNT(*) AS 'NULL_values_in_column'2
FROM `users`3
WHERE `department_id` IS NULL;Result:
create_tables.sql file:
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CREATE TABLE `users` (2
`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,3
`name` VARCHAR(50) NOT NULL,4
`surname` VARCHAR(50) NOT NULL,5
`department_id` INT(10) UNSIGNED,6
`salary` DECIMAL(15,2) NOT NULL,7
PRIMARY KEY (`id`)8
);insert_data.sql file:
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INSERT INTO `users`2
( `name`, `surname`, `department_id`, `salary`)3
VALUES4
('John', 'Stewart', 1, '6000'),5
('Chris', 'Brown', 2, '6000'),6
('Kate', 'Lewis', 3, '4000'),7
('Ailisa', 'Gomez', NULL, '4000'),8
('Gwendolyn', 'James', NULL, '4000'),9
('Simon', 'Collins', 4, '4000'),10
('Taylor', 'Martin', 2, '2000'),11
('Andrew', 'Thompson', NULL, '2000');