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diff --git a/avysokih/postgresql/command order/command_order.sql b/avysokih/postgresql/command order/command_order.sql
new file mode 100644
index 0000000..116fd41
--- /dev/null
+++ b/avysokih/postgresql/command order/command_order.sql	
@@ -0,0 +1,53 @@
+/*Задача 1: Какой будет порядок выполнения у запросов?
+
+SELECT name, age
+FROM users
+WHERE is_active = true AND country = 'Canada'
+ORDER BY age
+LIMIT 3;
+
+*/
+
+1. FROM users
+2. WHERE is_active = true AND country = 'Canada'
+3. SELECT name, age
+4. ORDER BY age
+5. LIMIT 3
+
+ /*
+SELECT country, COUNT(*) AS active_users
+FROM users
+WHERE is_active = true
+GROUP BY country
+HAVING COUNT(*) > 1;
+ */
+
+ 1. FROM users
+ 2. WHERE is_active = true
+ 3. GROUP BY country
+ 4. HAVING COUNT(*) > 1
+ 5. SELECT country, COUNT(*) AS active_users
+
+ /*
+SELECT country, AVG(age) AS avg_age
+FROM users
+GROUP BY country
+HAVING COUNT(*) >= 3 AND AVG(age) > 25;
+ */
+
+ 1. FROM users
+ 2. GROUP BY country
+ 3. HAVING COUNT(*) >= 3 AND AVG(age) > 25
+ 4. SELECT country, AVG(age) AS avg_age
+
+ /*
+SELECT name, age
+FROM users
+WHERE is_active = false AND age > 30
+ORDER BY name;
+ */
+  
+  1. FROM users
+  2. WHERE is_active = false AND age > 30
+  3. SELECT name, age
+  4. ORDER BY name
\ No newline at end of file
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diff --git a/avysokih/postgresql/filtration tasks/filtr_code.sql b/avysokih/postgresql/filtration tasks/filtr_code.sql
new file mode 100644
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--- /dev/null
+++ b/avysokih/postgresql/filtration tasks/filtr_code.sql	
@@ -0,0 +1,104 @@
+-- Создание и заполнение таблицы
+
+create table products_extended(
+id INT primary key,
+name TEXT,
+category TEXT,
+price DECIMAL,
+in_stock BOOLEAN,
+email_support TEXT
+);
+
+INSERT INTO products_extended (id, name, category, price, in_stock, email_support) VALUES
+(1, 'iPhone 14', 'smartphone', 799, TRUE, 'iphone@apple.com'),
+(2, 'MacBook Air', 'laptop', 1199, FALSE, NULL),
+(3, 'Galaxy S22', 'smartphone', 699, TRUE, 'galaxy@support.com'),
+(4, 'ThinkPad X1', 'laptop', 1399, TRUE, 'thinkpad@lenovo.com'),
+(5, 'iPad Pro', 'tablet', 999, FALSE, 'ipad@apple.com'),
+(6, 'Kindle Paperwhite', 'ebook_reader', 149, TRUE, NULL),
+(7, 'Mi Band 7', 'smartwatch', 49, TRUE, 'miband@xiaomi.com'),
+(8, 'Surface Pro', 'tablet', 1299, TRUE, 'surface@microsoft.com'),
+(9, 'Honor Pad X9', 'tablet', 219, TRUE, 'honor@support.com'),
+(10, 'Dell XPS 13', 'laptop', 1099, FALSE, 'dell@support.com');
+
+/*
+Задача 1:
+Выведи все товары, которые:
+- в наличии
+- НЕ относятся к `smartwatch` и `ebook_reader`
+- стоят от 300 до 1300
+И для них посчитай:
+1. price с наценкой 10%
+2. price с НДС 20%
+3. Статус: если email_support IS NULL, подставь нет почты, иначе — сам email
+*/
+
+
+select name, category, price, price * 1.1 as price_with_markup, price * 1.2 as price_with_vat, coalesce(email_support, 'нет почты') as status
+from  products_extended 
+where in_stock = true and category not in ('smartwatch', 'ebookreader') and price between 300 and 1300;
+
+/*
+Задача 2:
+Найти все товары:
+1. У которых цена меньше 150 или больше 1200
+2. У которых** есть email поддержки
+Для каждого выведи:
+1. Название
+2. Категорию
+3. Email
+4. Цену с прибавкой 25%
+5. Отметку `premium` — если цена > 1000
+*/
+
+select name, category, email_support, price * 1.25 as price_25, (price> 1000) as premium
+from products_extended
+where (price < 150 or price > 1200) and email_support is not null
+order by premium;
+
+/*
+Задача 3:
+Найди все товары:
+- где категория — `smartphone`, `laptop`, `tablet`
+- название НЕ содержит `'i'` (чтобы исключить Apple)
+- цена от 500 до 1300
+Выведи:
+- `id`, `name`, `category`, `price`
+- отсортируй по `id`
+*/
+
+select id, name, category, price 
+from products_extended
+where category in('smartphone', 'laptop', 'tablet') and name not like '%i%' and price between 500 and 1300
+order by id desc;
+
+/*
+Задача 4:
+Найди товары, у которых:
+- email_support IS NULL
+- они в наличии
+- стоят менее 800
+Выведи:
+- `name`, `category`, `price`
+- добавь колонку `comment`: `'нет поддержки'`
+*/
+
+select name, category, price, coalesce (email_support, 'нет поддержки') as comment
+from products_extended
+where email_support is null and in_stock is not null and price < 800;
+
+/*
+Задача 5:
+Найди товары, у которых:
+- название заканчивается на `'Pro'` ИЛИ содержит `'X'` внутри (например, `X1`, `XPS`)
+- в наличии
+- с ценой > 700
+Выведи:
+- `name`, `category`, `price`
+- флаг `premium` — `true`, если `price > 1000`, иначе `false`
+*/
+
+select name, category, price, (price>1000) as premium
+from products_extended
+where (name like '%Pro%' or name like '%X%') and in_stock is true and price > 700
+order by price desc;
\ No newline at end of file
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diff --git a/avysokih/postgresql/test_db.sql b/avysokih/postgresql/test_db.sql
new file mode 100644
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--- /dev/null
+++ b/avysokih/postgresql/test_db.sql
@@ -0,0 +1 @@
+CREATE TABLE test_db;#
\ No newline at end of file
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diff --git a/avysokih/postgresql/window functions/win_func_tasks.sql b/avysokih/postgresql/window functions/win_func_tasks.sql
new file mode 100644
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--- /dev/null
+++ b/avysokih/postgresql/window functions/win_func_tasks.sql	
@@ -0,0 +1,86 @@
+/*
+Задача 1:
+
+Для каждой категории показать 2 строки:
+- Самый дорогой товар с email'ом
+- Самый дорогой товар без email'а
+*/
+with with_mail as (
+select category, name, price, email_support
+from (
+select category, name, price, email_support,
+row_number() over (partition by category order by price desc) as rn
+from products_extended 
+where email_support is not null
+) t
+where rn = 1
+),
+without_mail as (
+select category, name, price, email_support
+from (
+select category, name, price, email_support,
+row_number() over (partition by category order by price desc) as rn
+from products_extended
+where email_support is null
+) t
+where rn = 1 
+)
+
+select * from with_mail
+union all
+select * from without_mail
+order by category;
+
+/*
+Задача 2:
+
+Для каждого товара показать:
+
+- `name` — название товара
+- `category` — категория товара
+- `price` — цена текущего товара
+- `next_price` — цена следующего товара внутри той же категории, упорядоченного по цене
+- `diff` — разница между ценой текущего товара и ценой следующего товара 
+(`price - next_price`)
+*/
+
+with t as(
+select name, category, price,
+lead(price) over (partition by category order by price) as next_price
+from products_extended)
+select name, category, price, next_price,
+price - next_price as diff
+from t order by category;
+
+/*
+Задача 3:
+
+Показать `category`, `name`, `price`, `cumulative_sales`
+
+Где `cumulative_sales` — это сумма `price` **внутри категории** по мере возрастания цены
+*/
+
+select category, name, price, 
+sum(price) over (partition by category order by price) as cumulative_sales
+from products_extended;
+
+/*
+Задача 4:
+
+Вывести `category`, `name`, `price`, `avg_price`, `is_above_avg`
+
+Где `avg_price` — средняя цена по категории
+
+`is_above_avg = true`, если `price > avg_price`
+
+*/
+
+
+with t as(
+select category, name, price,
+round(avg(price) over (partition by category), 1) as avg_price
+from products_extended)
+select category, name, price, avg_price,
+price > avg_price as is_above_avg
+from t order by category;
+