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Database

3465. Find Products with Valid Serial Numbers

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Description

Table: products

+--------------+------------+
| Column Name  | Type       |
+--------------+------------+
| product_id   | int        |
| product_name | varchar    |
| description  | varchar    |
+--------------+------------+
(product_id) is the unique key for this table.
Each row in the table represents a product with its unique ID, name, and description.

Write a solution to find all products whose description contains a valid serial number pattern. A valid serial number follows these rules:

  • It starts with the letters SN (case-sensitive).
  • Followed by exactly 4 digits.
  • It must have a hyphen (-) followed by exactly 4 digits.
  • The serial number must be within the description (it may not necessarily start at the beginning).

Return the result table ordered by product_id in ascending order.

The result format is in the following example.

 

Example:

Input:

products table:

+------------+--------------+------------------------------------------------------+
| product_id | product_name | description                                          |
+------------+--------------+------------------------------------------------------+
| 1          | Widget A     | This is a sample product with SN1234-5678            |
| 2          | Widget B     | A product with serial SN9876-1234 in the description |
| 3          | Widget C     | Product SN1234-56789 is available now                |
| 4          | Widget D     | No serial number here                                |
| 5          | Widget E     | Check out SN4321-8765 in this description            |
+------------+--------------+------------------------------------------------------+

Output:

+------------+--------------+------------------------------------------------------+
| product_id | product_name | description                                          |
+------------+--------------+------------------------------------------------------+
| 1          | Widget A     | This is a sample product with SN1234-5678            |
| 2          | Widget B     | A product with serial SN9876-1234 in the description |
| 5          | Widget E     | Check out SN4321-8765 in this description            |
+------------+--------------+------------------------------------------------------+

Explanation:

  • Product 1: Valid serial number SN1234-5678
  • Product 2: Valid serial number SN9876-1234
  • Product 3: Invalid serial number SN1234-56789 (contains 5 digits after the hyphen)
  • Product 4: No serial number in the description
  • Product 5: Valid serial number SN4321-8765

The result table is ordered by product_id in ascending order.

Solutions

Solution 1: Regex Matching

According to the problem statement, we need to find all products that contain a valid serial number, and the rules for a valid serial number are:

  • Starts with SN (case-sensitive).
  • Followed by 4 digits.
  • Must have a hyphen -, followed by 4 digits.

Based on the above rules, we can use a regular expression to match valid serial numbers, then filter out the products that contain valid serial numbers, and finally sort them in ascending order by product_id.

MySQL

# Write your MySQL query statement below
SELECT product_id, product_name, description
FROM products
WHERE description REGEXP '\\bSN[0-9]{4}-[0-9]{4}\\b'
ORDER BY 1;

Pandas

import pandas as pd


def find_valid_serial_products(products: pd.DataFrame) -> pd.DataFrame:
    valid_pattern = r"\bSN[0-9]{4}-[0-9]{4}\b"
    valid_products = products[
        products["description"].str.contains(valid_pattern, regex=True)
    ]
    valid_products = valid_products.sort_values(by="product_id")
    return valid_products