Staffelter Hof Winery is Germany's oldest business, established in 862 under the Carolingian dynasty. It has continued to serve customers through dramatic changes in Europe, such as the Holy Roman Empire, the Ottoman Empire, and both world wars. What characteristics enable a business to stand the test of time?
To help answer this question, BusinessFinancing.co.uk researched the oldest company still in business in almost every country and compiled the results into several CSV files. This dataset has been cleaned.
Having useful information in different files is a common problem. While it's better to keep different types of data separate for data storage, you'll want all the data in one place for analysis. You'll use joining and data manipulation to work with this data and better understand the world's oldest businesses.
The Data
businesses and new_businesses
| Column | Description |
|---|---|
business | Name of the business (varchar) |
year_founded | Year the business was founded (int) |
category_code | Code for the business category (varchar) |
country_code | ISO 3166-1 three-letter country code (char) |
countries
| Column | Description |
|---|---|
country_code | ISO 3166-1 three-letter country code (varchar) |
country | Name of the country (varchar) |
continent | Name of the continent the country exists in (varchar) |
categories
| Column | Description |
|---|---|
category_code | Code for the business category (varchar) |
category | Description of the business category (varchar) |
Exercice 1
-- What is the oldest business on each continent?
WITH rank_per_continent AS (
SELECT
c.continent,
c.country,
b.business,
b.year_founded,
ROW_NUMBER () OVER (PARTITION BY continent ORDER BY year_founded) AS rank
FROM
businesses AS b
INNER JOIN
countries AS c
ON b.country_code = c.country_code
)
SELECT
continent,
country,
business,
year_founded
FROM
rank_per_continent
WHERE
rank = 1
;Exercice 2
-- How many countries per continent lack data on the oldest businesses
-- Does including the `new_businesses` data change this?
WITH
all_businesses AS (
SELECT
*
FROM
businesses AS b
UNION
SELECT
*
FROM
new_businesses AS nb
),
countries_without_businesses AS (
SELECT
ab.business,
ab.year_founded,
ab.category_code,
ab.country_code,
c.country,
c.continent
FROM
all_businesses AS ab
RIGHT JOIN
countries AS c
ON ab.country_code = c.country_code
)
SELECT
continent,
COUNT(*) AS countries_without_businesses
FROM
countries_without_businesses
WHERE
business IS NULL
GROUP BY
continent
;Exercice 3
-- Which business categories are best suited to last over the course of centuries?
WITH everything AS (
SELECT
b.business,
b.year_founded,
co.country,
co.continent,
ca.category
FROM
businesses AS b
INNER JOIN
countries AS co ON b.country_code = co.country_code
INNER JOIN
categories AS ca ON b.category_code = ca.category_code
),
everything_ranked AS (
SELECT
*,
RANK () OVER(PARTITION BY continent, category ORDER BY year_founded) AS rank
FROM
everything
)
SELECT
continent,
category,
year_founded
FROM
everything_ranked
WHERE
rank = 1
;