My issue
SELECT
dps.product_id,
dps.units_sold,
dps.month
FROM
division_product_sales dps
JOIN
product_catalog pc ON dps.product_id = pc.product_id
WHERE
(dps.product_id, dps.units_sold) IN (
SELECT
product_id,
MIN(units_sold) AS min_units_sold
FROM
division_product_sales
GROUP BY
product_id
)
ORDER BY
dps.product_id;
debug
My code
SELECT
dps.product_id,
dps.units_sold,
dps.month
FROM
division_product_sales dps
JOIN
product_catalog pc ON dps.product_id = pc.product_id
WHERE
(dps.product_id, dps.units_sold) IN (
SELECT
product_id,
MIN(units_sold) AS min_units_sold
FROM
division_product_sales
GROUP BY
product_id
)
ORDER BY
dps.product_id;
Learning course: Database management systems
Problem Link: Project - Correlated Subquery and Table Join in Database management systems