MySQL: UNIQUE constraint

Описание к видео MySQL: UNIQUE constraint

#MySQL #tutorial #course

00:00:00 add UNIQUE CONSTAINT to a new table
00:01:12 add UNIQUE CONSTAINT to an existing table
00:02:00 demonstration

CREATE TABLE products (
product_id INT,
product_name varchar(25) UNIQUE,
price DECIMAL(4, 2)
);

ALTER TABLE products
ADD CONSTRAINT
UNIQUE (product_name);

INSERT INTO products
VALUES (100, 'hamburger', 3.99),
(101, 'fries', 1.89),
(102, 'soda', 1.00),
(103, "ice cream", 1.49);

SELECT * FROM products;

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