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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