Select

Table of Contents

• 1757. Recyclable and Low Fat Products (Easy)
• 584. Find Customer Referee (Easy)
• 595. Big Countries (Easy)
• 1148. Article Views I (Easy)
• 1683. Invalid Tweets (Easy)

1757. Recyclable and Low Fat Products

• LeetCode | LeetCode CH (Easy)

• Tags: database

1757. Recyclable and Low Fat Products

Input:
Products table:
+-------------+----------+------------+
| product_id  | low_fats | recyclable |
+-------------+----------+------------+
| 0           | Y        | N          |
| 1           | Y        | Y          |
| 2           | N        | Y          |
| 3           | Y        | Y          |
| 4           | N        | N          |
+-------------+----------+------------+
Output:
+-------------+
| product_id  |
+-------------+
| 1           |
| 3           |
+-------------+

1757. Recyclable and Low Fat Products

SELECT product_id
FROM
    products
WHERE
    low_fats = 'Y'
    AND recyclable = 'Y';

584. Find Customer Referee

• LeetCode | LeetCode CH (Easy)

• Tags: database

584. Find Customer Referee

-- 1.
SELECT NAME
FROM
    CUSTOMER
WHERE
    REFEREE_ID <> 2
    OR REFEREE_ID IS NULL;

-- 2.
SELECT NAME
FROM
    CUSTOMER
WHERE
    COALESCE(REFEREE_ID, -1) <> 2;

-- 3.
SELECT NAME
FROM
    CUSTOMER
WHERE
    COALESCE(REFEREE_ID, -1) <> 2;

595. Big Countries

• LeetCode | LeetCode CH (Easy)

• Tags: database

595. Big Countries

SELECT
    NAME,
    POPULATION,
    AREA
FROM
    WORLD
WHERE
    POPULATION >= 25000000
    OR AREA >= 3000000;

1148. Article Views I

• LeetCode | LeetCode CH (Easy)

• Tags: database

1148. Article Views I

SELECT DISTINCT author_id AS id
FROM
    views
WHERE
    author_id = viewer_id
ORDER BY
    id ASC;

1683. Invalid Tweets

• LeetCode | LeetCode CH (Easy)

• Tags: database

1683. Invalid Tweets

SELECT tweet_id
FROM
    tweets
WHERE
    CHAR_LENGTH(content) > 15;

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