switch device

BD_4s/task 1.sql

@@ -0,0 +1,72 @@
+--2
+SELECT *
+FROM bd_departments
+WHERE LENGTH(street) = POWER(SQRT(75 + LENGTH(street)), 2) / 4;
+
+INSERT INTO bd_departments VALUES
+(35,'meow', 407596, 'aaaaaaaaaaaaaaaaaaaaaaaaa', 2, 'MSK');
+--4
+CREATE TABLE employees_backup AS
+SELECT *, 
+    CASE 
+        WHEN random() < 0.5 THEN 'Active'
+        ELSE 'Inactive'
+    END AS employee_status
+FROM bd_employees;
+SELECT * FROM employees_backup;
+--5
+SELECT e.employee_id, e.first_name, e.last_name, e.manager_id
+FROM employees e
+JOIN employees m ON e.manager_id = m.employee_id
+WHERE LENGTH(m.last_name) > 6;
+
+--3--
+
+DO $$
+DECLARE
+BEGIN
+    RAISE NOTICE 'Шахматная доска:';
+    CALL chess('z9', 'C');
+ 
+
+    RAISE NOTICE 'Размещение фигуры А на клетке A5:';
+    CALL chess('a5', ' A ');
+
+
+    RAISE NOTICE 'Размещение фигуры У на клетке H4:';
+    CALL chess('h4', ' Y ');
+
+
+END $$;
+
+
+
+CREATE OR REPLACE PROCEDURE chess(pos varchar, bukva char) AS $$
+DECLARE
+    board text;
+    queen_col integer;
+    queen_row integer;
+BEGIN
+    queen_col := ascii(substring(pos from 1 for 1)) - 96;
+    queen_row := substring(pos from 2)::integer;
+	
+    FOR i IN 1..8 LOOP
+        board := '';
+		
+        FOR j IN 1..8 LOOP
+            IF i = queen_row AND j = queen_col THEN
+                board := board || bukva;
+            ELSE
+                IF (i + j) % 2 = 0 THEN
+                    board := board || ' б ';
+                ELSE
+                    board := board || ' ч ';
+                END IF;
+            END IF;
+        END LOOP;
+		
+        RAISE NOTICE '%', board;
+    END LOOP;
+END
+$$ LANGUAGE plpgsql;
+SELECT chess('c3');