Last updated on October 10th, 2024 at 12:04 am

This Leetcode problem Product Sales Analysis III LeetCode Solution is done in SQL.

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Product Sales Analysis III LeetCode Solution

Problem Statement

(sale_id, year) is the primary key (combination of columns with unique values) of this table. product_id is a foreign key (reference column) to Product table.
Each row of this table shows a sale on the product product_id in a certain year. Note that the price is per unit.

product_id is the primary key (column with unique values) of this table. Each row of this table indicates the product name of each product.

Write a solution to select the product id, year, quantity, and price for the first year of every product sold.

Return the resulting table in any order.

The result format is in the following example.

Example 1:
Input:

Output:

1. Product Sales Analysis III LeetCode Solution MySQL

select 
  product_id, 
  year as first_year, 
  quantity, 
  price 
from 
  Sales 
where 
  (product_id, year) in (
    select 
      product_id, 
      min(year) as year 
    from 
      Sales 
    group by 
      product_id
  );

2. Product Sales Analysis III LeetCode Solution Pandas

import pandas as pd

def sales_analysis(sales: pd.DataFrame, product: pd.DataFrame) -> pd.DataFrame:
  df = sales.groupby('product_id', as_index=False)['year'].min()
  return sales.merge(df, on='product_id', how='inner')\
    .query('year_x == year_y')\
    .rename(columns={'year_x': 'first_year'})\
    [['product_id', 'first_year', 'quantity', 'price']]