EN
MySQL - search for NULL values in multiple columns
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In this article, we would like to show you how to find rows with NULL values in many columns in MySQL.
Quick solution:
SELECT *
FROM `table_name`
WHERE `column1` IS NULL AND `column2` IS NULL AND `columnN` IS NULL;
SELECT *
FROM `users`
WHERE COALESCE(`column1`, `column2`) IS NULL;
Practical example
To show how to find rows with NULL values in many columns, we will use the following table:
Note:
At the end of this article you can find database preparation SQL queries.
Example 1
In this example, we will select all rows with NULL value both in email and department_id column using IS NULL and AND keywords.
Query:
SELECT *
FROM `users`
WHERE `email` IS NULL AND `department_id` IS NULL;
Result:
Example 2
In this example, we will select all rows with NULL value both in email and department_id column using COALESCE() function.
Query:
SELECT *
FROM `users`
WHERE COALESCE(`email`, `department_id`) IS NULL;
Result:
Database preparation
create_tables.sql file:
CREATE TABLE `users` (
`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`name` VARCHAR(50) NOT NULL,
`surname` VARCHAR(50) NOT NULL,
`email` VARCHAR(100),
`department_id` INT(10) UNSIGNED,
`salary` DECIMAL(15,2) NOT NULL,
PRIMARY KEY (`id`)
);
insert_data.sql file:
INSERT INTO `users`
( `name`, `surname`, `email`, `department_id`, `salary`)
VALUES
('John', 'Stewart', 'john@email.com', 1, '3512.00'),
('Chris', 'Brown', 'chris@email.com', 2, '1344.00'),
('Kate', 'Lewis', NULL, 3, '6574.00'),
('Ailisa', 'Gomez', 'ailisa@email.com', 2, '6500.00'),
('Gwendolyn', 'James', NULL, NULL, '4200.00'),
('Simon', 'Collins', NULL, 4, '3320.00'),
('Taylor', 'Martin', NULL, NULL, '1500.00'),
('Andrew', 'Thompson', 'andrew@email.com', NULL, '2100.00');