Lesson09

lesson09/task1.sql

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+#Задание№1
+START TRANSACTION;
+INSERT INTO sample.users (name, birthday_at, created_at, updated_at)
+	select u.name, u.birthday_at, u.created_at, u.updated_at 
+		from shop.users as u
+		where u.id =1;
+COMMIT;
+
+#Задание№2
+use shop;
+drop view if exists prod_view;
+CREATE VIEW prod_view AS 
+	select p.name as prod_name, c.name as cat_name
+		from products as p, catalogs as c
+		where p.catalog_id = c.id;
+
+#Задание№3
+use shop;
+drop table if exists tb_create_at;
+CREATE TABLE tb_create_at (
+  id SERIAL PRIMARY KEY,
+  created_at DATETIME
+);
+INSERT INTO tb_create_at (created_at) VALUES
+  ('2018-08-01'),
+  ('2018-08-04'),
+  ('2018-08-16'),
+  ('2018-08-17'),
+  ('2018-08-19'),
+  ('2018-08-21'),
+  ('2018-08-22');
+
+SELECT `x`.sequence_date, IF(`x`.sequence_date in (select created_at from tb_create_at),1,0) as `flag`
+  FROM (SELECT DATE_ADD('2018-08-01', INTERVAL `n`.`id` - 1 day) as sequence_date
+          FROM (SELECT  @N := @N +1 AS id 
+					FROM mysql.help_relation , (SELECT @N:=0) dum LIMIT 31) `n`
+  WHERE DATE_ADD('2018-01-01', INTERVAL `n`.`id` -1 DAY) <= '2018-12-30' ) x;
+
+#Задание№4
+use shop;
+select created_at
+into @search_date
+from (select * 
+		from tb_create_at as t1
+		order by t1.created_at desc		
+		limit 5) as t2
+order by t2.created_at
+limit 1;
+delete from tb_create_at as tb
+	where tb.created_at < @search_date;
+
+
+
+

lesson09/task2.sql

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+#Задание №1
+drop user if exists 'shop'@'localhost';
+drop user if exists 'shop_read'@'localhost';
+CREATE USER 'shop'@'localhost' IDENTIFIED WITH sha256_password BY 'pass';
+CREATE USER 'shop_read'@'localhost' IDENTIFIED WITH sha256_password BY 'pass';
+
+GRANT ALL ON shop.* TO 'shop'@'localhost';
+GRANT SELECT  ON shop.* TO 'shop_read'@'localhost';
+
+
+
+
+#Задание №2
+use shop;
+drop table if exists accounts;
+CREATE TABLE accounts (
+  id SERIAL PRIMARY KEY,
+  name VARCHAR(255),
+  `password` VARCHAR(255)
+) ;
+
+INSERT INTO accounts
+  (name, `password`)
+VALUES
+  ('alex', 'pass1'),
+  ('john', 'pass2'),
+  ('ivan', 'pass3');
+
+
+drop view if exists accounts_view;
+CREATE VIEW accounts_view AS 
+	select *
+		from accounts;
+
+drop user if exists 'user_read'@'localhost';
+CREATE USER 'user_read'@'localhost' IDENTIFIED WITH sha256_password BY 'pass';
+
+GRANT select ON shop.accounts_view TO 'user_read'@'localhost';
+
+
+
+

lesson09/task3.sql

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+#Задание №1
+use shop;
+drop procedure if exists hello;
+delimiter //
+CREATE PROCEDURE hello ()
+begin
+     set @a = HOUR(NOW());
+     SELECT case 
+		  when (0 <= @a) && (@a < 6) then 'Доброй ночи'	
+		  when (6 <= @a) && (@a < 12) then 'Доброе утро'	
+		  when (12 <= @a) && (@a < 18) then 'Добрый день'
+		  when (18 <= @a) && (@a < 24) then 'Добрый вечер'
+	     end as hello;
+end//
+
+call hello();
+
+
+
+
+
+
+#Задание №2
+use shop;
+drop trigger if exists check_update_products;
+delimiter //
+CREATE TRIGGER check_update_products BEFORE UPDATE ON products
+FOR EACH ROW BEGIN
+  IF (NEW.name is null  and NEW.description is null or
+      old.name is null and NEW.description is null or
+      NEW.name is null and old.description is null) THEN
+	SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Update canceled';
+  END IF;
+END//
+delimiter ;
+
+UPDATE products as p SET p.description="wd", p.name="wqd"
+WHERE p.id=1;
+
+drop trigger if exists check_insert_products;
+delimiter //
+CREATE TRIGGER check_insert_products BEFORE insert ON products
+FOR EACH ROW BEGIN
+  IF (NEW.name is null  and NEW.description is null) THEN
+	SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Insert canceled';
+  END IF;
+END//
+
+INSERT INTO products
+  (price, catalog_id)
+VALUES
+  (7890.00, 1);
+
+
+
+
+#Задание №2
+use shop;
+drop procedure if exists fib;
+delimiter //
+CREATE PROCEDURE fib(n INT)
+begin
+  DECLARE m INT default 0;
+  DECLARE k INT DEFAULT 1;
+  DECLARE i INT;
+  DECLARE tmp INT;
+
+  SET m=0;
+  SET k=1;
+  SET i=1;
+
+  WHILE (i<=n) DO
+    SET tmp=m+k;
+    SET m=k;
+    SET k=tmp;
+    SET i=i+1;
+  END WHILE;
+  select m;
+ end//
+
+ call fib(10)