MariaDB 10.5

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CREATE TABLE customers (
    id int auto_increment primary key,
    order_date DATE,
    customerID VARCHAR(255)
);

INSERT INTO customers
(order_date, customerID
)
VALUES 
('2020-01-15', 'Customer_01'),
('2020-02-03', 'Customer_01'),
('2020-02-15', 'Customer_01'),
('2020-03-18', 'Customer_01'),
('2020-03-20', 'Customer_01'),
('2020-04-22', 'Customer_01'),
('2021-01-19', 'Customer_01'),

('2020-01-25', 'Customer_02'),
('2020-02-26', 'Customer_02'),
('2020-11-23', 'Customer_02'),
('2021-01-17', 'Customer_02'),
('2021-02-20', 'Customer_02');


/* Count orders per year */

SELECT 
order_date, 
(row_number() over(PARTITION BY YEAR(order_date - INTERVAL 2 MONTH), customerID ORDER BY order_date)) AS rolling_count
FROM customers
ORDER BY 1;


order_date
rolling_count


2020-01-15
1

2020-01-25
1

2020-02-03
2

2020-02-15
3

2020-02-26
2

2020-03-18
1

2020-03-20
2

2020-04-22
3

2020-11-23
1

2021-01-17
2

2021-01-19
4

2021-02-20
3


/* Only display the first order */

SELECT
order_date,
(CASE WHEN t.rolling_count > 1 THEN 0 ELSE t.rolling_count END) AS quantity
FROM 

  (SELECT 
  order_date, 
  (row_number() over(PARTITION BY YEAR(order_date - INTERVAL 2 MONTH), customerID ORDER BY order_date)) AS rolling_count
  FROM customers
  ORDER BY 1
  ) t
  
GROUP BY 1
ORDER BY 1;


order_date
quantity


2020-01-15
1

2020-01-25
1

2020-02-03
0

2020-02-15
0

2020-02-26
0

2020-03-18
1

2020-03-20
0

2020-04-22
0

2020-11-23
1

2021-01-17
0

2021-01-19
0

2021-02-20
0

order_date	rolling_count
2020-01-15	1
2020-01-25	1
2020-02-03	2
2020-02-15	3
2020-02-26	2
2020-03-18	1
2020-03-20	2
2020-04-22	3
2020-11-23	1
2021-01-17	2
2021-01-19	4
2021-02-20	3