SQL select data and grouping data by date range

Question

I have table with data like this

price	date	type
1000	2021-03-13	A
1000	2021-03-14	A
1000	2021-03-15	A
1300	2021-03-16	A
1000	2021-03-17	A
1300	2021-03-18	A
1000	2021-03-19	A
1500	2021-03-20	A
1500	2021-03-21	A
1500	2021-03-22	A
2000	2021-03-13	B
2000	2021-03-14	B
2000	2021-03-15	B
2000	2021-03-16	B
2000	2021-03-17	B

I want to query data like this

price	startDate	endDate	type
1000	2021-03-13	2021-03-15	A
1300	2021-03-16	2021-03-16	A
1000	2021-03-17	2021-03-17	A
1300	2021-03-18	2021-03-18	A
1000	2021-03-19	2021-03-19	A
1500	2021-03-20	2021-03-22	A
2000	2021-03-13	2021-03-17	B

my current sql below but it is not correct at all

SELECT MIN(date) as startDate, MAX(date) as endDate, price, type                                      
                            FROM prices 
                            GROUP BY type, price
                            ORDER BY type, MIN(date)

Answer 1

This is a gaps and islands problem, and one simple way to handle it uses the difference in row numbers method. Assuming you are using MySQL 8+, the following should work:

WITH cte AS (
    SELECT *, ROW_NUMBER() OVER (PARTITION BY type ORDER BY date) rn1,
              ROW_NUMBER() OVER (PARTITION BY type, price ORDER BY date) rn2
    FROM prices
)

SELECT price, MIN(date) AS startDate, MAX(date) AS endDate, type
FROM cte
GROUP BY price, type, rn1 - rn2
ORDER BY type, startDate;

Demo