select 
    p.product_id
    ,product_name
    ,competitor_name
    ,total_sales_amount_of_product
    ,(total_sales_amount_of_product-total_competitor_sales_amount_2023) as sales_difference_with_competitor
from oppo_products_detail p 
join
    (select 
        product_id,
        sum(quarter_1_sales_amount+quarter_2_sales_amount+quarter_3_sales_amount+quarter_4_sales_amount) as total_sales_amount_of_product
    from sales_info group by 1) sa using(product_id) 
 join competitor_analysis c using(product_id)
 order by 1;