MariaDB 10.3

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/* Sales */
CREATE TABLE sales (
    id int auto_increment primary key,
    category VARCHAR(255),
    sales_date DATE,
    sales_volume INT
);

INSERT INTO sales
(category, sales_date, sales_volume
)
VALUES 
("Category_01", "2020-01-03", "500"),
("Category_01", "2020-04-15", "700"),
("Category_01", "2020-08-27", "180"),
("Category_01", "2020-09-29", "320"),
("Category_02", "2020-07-17", "420"),
("Category_02", "2020-12-24", "350"),
("Category_02", "2020-12-08", "570"),
("Category_03", "2020-01-10", "180"),
("Category_03", "2020-10-20", "970");

/* Return Risk */
CREATE TABLE return_risk (
    id int auto_increment primary key,
    category VARCHAR(255),
    quarter VARCHAR(255),
    return_risk_rate DECIMAL(5,2)
);

INSERT INTO return_risk
(category, quarter, return_risk_rate
)
VALUES 
("Category_01", "2020-Q1", "0.40"),
("Category_01", "2020-Q2", "0.45"),
("Category_01", "2020-Q3", "0.52"),
("Category_01", "2020-Q4", "0.67"),
("Category_02", "2020-Q1", "0.32"),
("Category_02", "2020-Q2", "0.47"),
("Category_02", "2020-Q3", "0.25"),
("Category_02", "2020-Q4", "0.32"),
("Category_03", "2020-Q1", "0.40"),
("Category_03", "2020-Q2", "0.52"),
("Category_03", "2020-Q3", "0.48"),
("Category_03", "2020-Q4", "0.61");

category	quarter	sales	return_risk_%	return_risk_value
Category_01	2020-Q1	500	0.40	200.00
Category_01	2020-Q2	700	0.45	315.00
Category_01	2020-Q3	500	0.52	260.00
Category_01	2020-Q4	0	0.67	0.00
Category_02	2020-Q1	0	0.32	0.00
Category_02	2020-Q2	0	0.47	0.00
Category_02	2020-Q3	420	0.25	105.00
Category_02	2020-Q4	920	0.32	294.40
Category_03	2020-Q1	180	0.40	72.00
Category_03	2020-Q2	0	0.52	0.00
Category_03	2020-Q3	0	0.48	0.00
Category_03	2020-Q4	970	0.61	591.70