update filtr tasks

avysokih/postgresql/filtration tasks/filtr_code.sql

@@ -0,0 +1,46 @@
+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');
+
+select * from products_extended
+where in_stock = true and category not in ('smartwatch', 'ebookreader') and price between 300 and 1300;
+
+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;
+
+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;
+
+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;
+
+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;
+
+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;