added lab4

Lab/Lab#4/lab4.sql

@@ -0,0 +1,37 @@
+CREATE table staff(
+	id integer primary key,
+	name varchar(64) NOT NULL,
+	department varchar(64) NOT NULL
+);
+
+CREATE SEQUENCE staff_id_seq
+	START WITH 12
+	CYCLE
+	INCREMENT BY 8
+	CACHE 100;
+	
+
+INSERT INTO staff VALUES
+	(nextval('staff_id_seq'), 'Ivan Makarenko', 'Director');
+	
+INSERT INTO staff
+	(SELECT nextval('staff_id_seq'), last_name, department_name
+	 FROM employees e JOIN departments d ON e.department_id = d.department_id);
+	 
+UPDATE staff SET department = 'Innovations department'
+	WHERE id < 40;
+	
+DELETE FROM staff 
+	WHERE name ILIKE('%K%');
+	
+WITH RECURSIVE tmp AS (
+  SELECT employee_id, first_name, last_name, manager_id, 1 AS level
+  FROM employees
+  WHERE manager_id = 100
+  UNION ALL
+  SELECT e.employee_id, e.first_name, e.last_name, e.manager_id, t.level + 1
+  FROM employees e
+  JOIN tmp t ON e.manager_id = t.employee_id
+)
+SELECT first_name, last_name
+FROM tmp;