Lesson07

lesson07/task1.sql

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+select distinct u.name 
+from orders as o
+	join
+      users as u on u.id = o.user_id 

lesson07/task2.sql

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+use newdb;
+
+select p.name as product_name, c.name as catalog_name  
+from  newdb.catalogs as c
+        join 
+      products as p on c.id = p.catalog_id

lesson07/task3.sql

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+DROP DATABASE IF EXISTS flights;
+CREATE DATABASE flights;
+USE flights;
+
+DROP TABLE IF EXISTS flights;
+CREATE TABLE flights (
+  id SERIAL PRIMARY KEY,
+  `from` VARCHAR(255),
+  `to` VARCHAR(255)
+);
+
+INSERT INTO flights (`from`,`to`) VALUES
+  ('moscow', 'omsk'),
+  ('novgorod', 'kazan'),
+  ('irkutsk', 'moscow'),
+  ('omsk', 'irkutsk'),
+  ('moscow', 'kazan');
+
+DROP TABLE IF EXISTS cities;
+CREATE TABLE cities (
+  label VARCHAR(255),
+  name VARCHAR(255)
+);
+
+INSERT INTO cities (label, name) VALUES
+  ('moscow', '������'),
+  ('irkutsk', '�������'),
+  ('novgorod', '��������'),
+  ('kazan', '������'),
+  ('omsk', '����');
+
+ select f.id, c1.name as `from`, c2.name as `to` 
+ from flights as f
+ 	join 
+ 	  cities as c1 on f.`from` = c1.label
+ 	join
+ 	  cities as c2 on f.`to` = c2.label
+ order by f.id