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PostgreSQL - 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 PostgreSQL.
Quick solution:
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SELECT *2
FROM "table_name" 3
WHERE "column1" IS NULL AND "column2" IS NULL AND "columnN" IS NULL;xxxxxxxxxx1
SELECT *2
FROM "users"3
WHERE COALESCE("column1", "column2") IS NULL;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.
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:
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SELECT *2
FROM "users"3
WHERE "email" IS NULL AND "department_id" IS NULL;Result:
In this example, we will select all rows with NULL value both in email and department_id column using COALESCE() function.
Query:
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SELECT *2
FROM "users"3
WHERE COALESCE("email", "department_id") IS NULL;Result:
create_tables.sql file:
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CREATE TABLE "users" (2
"id" SERIAL,3
"name" VARCHAR(50) NOT NULL,4
"surname" VARCHAR(50) NOT NULL,5
"email" VARCHAR(100),6
"department_id" INTEGER,7
"salary" DECIMAL(15,2) NOT NULL,8
PRIMARY KEY ("id")9
);insert_data.sql file:
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INSERT INTO "users"2
( "name", "surname", "email", "department_id", "salary")3
VALUES4
('John', 'Stewart', 'john@email.com', 1, '3512.00'),5
('Chris', 'Brown', 'chris@email.com', 2, '1344.00'),6
('Kate', 'Lewis', NULL, 3, '6574.00'),7
('Ailisa', 'Gomez', 'ailisa@email.com', 2, '6500.00'),8
('Gwendolyn', 'James', NULL, NULL, '4200.00'),9
('Simon', 'Collins', NULL, 4, '3320.00'),10
('Taylor', 'Martin', NULL, NULL, '1500.00'),11
('Andrew', 'Thompson', 'andrew@email.com', NULL, '2100.00');