EN
PostgreSQL - Delete query
0
points
In this article, we would like to show you how to make DELETE
query in PostgreSQL.
Quick solution:
DELETE FROM "table_name"
WHERE "column_name" = some_value;
Note:
where
some_value
is either a number or a string wrapped with single quotation marks''
.
Practical example
To show how DELETE statement works, 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 delete user whose id
= 8
.
Query:
DELETE FROM "users"
WHERE "id" = 8;
Result:
Example 2
In this example, we will delete user whose name
= John
.
Query:
DELETE FROM "users"
WHERE "name" = 'John';
Result:
Database preparation
create_tables.sql
file:
CREATE TABLE "users" (
"id" SERIAL,
"name" VARCHAR(50) NOT NULL,
"surname" VARCHAR(50) NOT NULL,
"department_id" INTEGER,
"salary" DECIMAL(15,2) NOT NULL,
PRIMARY KEY ("id")
);
insert_data.sql
file:
INSERT INTO "users"
( "name", "surname", "department_id", "salary")
VALUES
('John', 'Stewart', 1, '3512.00'),
('Chris', 'Brown', 2, '1344.00'),
('Kate', 'Lewis', 3, '6574.00'),
('Ailisa', 'Gomez', NULL, '6500.00'),
('Gwendolyn', 'James', 2, '4200.00'),
('Simon', 'Collins', 4, '3320.00'),
('Taylor', 'Martin', 2, '1500.00'),
('Andrew', 'Thompson', NULL, '2100.00');