anton
81 lines
2.2 KiB
SQL
81 lines
2.2 KiB
SQL
/*
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Задача 1:
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Для каждой категории показать 2 строки:
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- Самый дорогой товар с email'ом
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- Самый дорогой товар без email'а
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*/
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with with_mail as (
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select category, name, price, email_support
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from (
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select category, name, price, email_support,
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row_number() over (partition by category order by price desc) as rn
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from products_extended
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where email_support is not null
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) t
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where rn = 1
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),
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without_mail as (
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select category, name, price, email_support
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from (
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select category, name, price, email_support,
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row_number() over (partition by category order by price desc) as rn
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from products_extended
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where email_support is null
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) t
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where rn = 1
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)
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select * from with_mail
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union all
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select * from without_mail
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order by category;
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/*
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Задача 2:
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Для каждого товара показать:
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- `name` — название товара
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- `category` — категория товара
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- `price` — цена текущего товара
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- `next_price` — цена следующего товара внутри той же категории, упорядоченного по цене
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- `diff` — разница между ценой текущего товара и ценой следующего товара
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(`price - next_price`)
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*/
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select name, category, price, lead(price) over(partition by category order by price) as next_price,
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price - lead(price) over(partition by category order by price) as diff
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from products_extended;
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/*
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Задача 3:
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Показать `category`, `name`, `price`, `cumulative_sales`
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Где `cumulative_sales` — это сумма `price` **внутри категории** по мере возрастания цены
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*/
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select category, name, price,
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sum(price) over (partition by category order by price) as cumulative_sales
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from products_extended;
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/*
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Задача 4:
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Вывести `category`, `name`, `price`, `avg_price`, `is_above_avg`
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Где `avg_price` — средняя цена по категории
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`is_above_avg = true`, если `price > avg_price`
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*/
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select category, name, price,
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round(avg(price) over (partition by category), 1) as avg_price,
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price > avg(price) over (partition by category) as is_above_avg
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from products_extended;
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