Update 3_a.sql

3_a.sql

@@ -1,39 +1,19 @@
--- Erotima 3a
-DROP TRIGGER IF EXISTS carExists ON service_history;
-CREATE TRIGGER carExists
-  BEFORE INSERT ON service_history
-  FOR EACH ROW
-  EXECUTE PROCEDURE carExists();
-
-DROP FUNCTION IF EXISTS carExists();
-CREATE FUNCTION carExists()
-  RETURNS TRIGGER AS
-$BODY$
-BEGIN
-  IF NOT EXISTS(SELECT id from car_warehouse WHERE car_warehouse.id = NEW.car_id ) THEN
-    INSERT INTO car_warehouse(id, owner_id, plate, make_id, model_id, manufacturing_date, condition)
-    VALUES (99999, null, null, 2, 22, 2009, 'used');
-  END IF;
-  RETURN NEW;
-END;
-$BODY$
-LANGUAGE 'plpgsql';
-
--- To problima einai oti ama den iparxei idi to amaksi mesa mesa sto car_warehouse kai prepei na dimiourgithei,
--- tha prepei, ipoxreotika afou einai metaxeirismeno, kata tin dimiourgia tou na exei owner_id, kai plate_num...
--- kati to opoio den einai efikto giati sto insert into den parexontai auta ta dedomena
-INSERT INTO service_history(car_id, tech_id, cost, start_date, end_date) VALUES (99999, 11, 999.99, now(), null);
-
--- Mia lisi tha einai itan i dimiourgia temp table... Alla kai pali den exoume elegxo an iparxei o idioktitis...
+-- Temporary table
 DROP TABLE temp_car_service;
 CREATE TEMPORARY TABLE temp_car_service(
   id SERIAL NOT NULL ,
-  owner_id INT ,
+  -- customer
+  first_name VARCHAR(60) NOT NULL ,
+  last_name VARCHAR(60) NOT NULL ,
+  afm NUMERIC(8,0) NOT NULL,
+  email VARCHAR(60) NOT NULL,
+  phone VARCHAR(10) NOT NULL,
+  -- car_warhouse
   plate PLATE_NUM,
   make_id INT NOT NULL,
   model_id INT NOT NULL,
   manufacturing_date NUMERIC(4,0),
-  car_id INT NOT NULL,
+  -- service history
   tech_id INT NOT NULL,
   cost FLOAT NOT NULL ,
   start_date DATE NOT NULL ,
@@ -42,34 +22,76 @@ CREATE TEMPORARY TABLE temp_car_service(
   PRIMARY KEY (id)
 );
 
-DROP FUNCTION IF EXISTS carExists2();
-CREATE FUNCTION carExists2()
+-- Function that will be called by trigger
+DROP FUNCTION IF EXISTS carExists();
+CREATE FUNCTION carExists()
   RETURNS TRIGGER AS
 $BODY$
 DECLARE latest_car_id INT;
+DECLARE latest_owner_id INT;
 BEGIN
-  IF NOT EXISTS(SELECT id from car_warehouse WHERE car_warehouse.id = NEW.car_id ) THEN
+  IF NOT EXISTS(SELECT plate as a from car_warehouse WHERE plate = NEW.plate::plate_num) THEN
+
+    -- Firstly we instert the new customer
+    INSERT INTO customers(first_name, last_name, afm, email, phone)
+    VALUES (NEW.first_name, NEW.last_name, NEW.afm, NEW.email, NEW.phone);
+
+    -- Then we select his id to use it later
+    SELECT id INTO latest_owner_id FROM customers
+    ORDER BY id DESC LIMIT 1;
+
+    -- Secondly we insert the car in the car warehouse
     INSERT INTO car_warehouse(owner_id, plate, make_id, model_id, manufacturing_date, condition)
-    VALUES (NEW.owner_id, NEW.plate, NEW.model_id, NEW.make_id, NEW.manufacturing_date, 'used');
+    VALUES (latest_owner_id, NEW.plate, NEW.model_id, NEW.make_id, NEW.manufacturing_date, 'used');
 
+    -- Then we select the car's id to use it later
     SELECT id INTO latest_car_id FROM car_warehouse
     ORDER BY id DESC LIMIT 1;
 
+    -- Finally we insert tha data in service_history
     INSERT INTO service_history(car_id, tech_id, cost, start_date, end_date) VALUES (latest_car_id, NEW.tech_id, NEW.cost, NEW.start_date, NEW.end_date);
+
   ELSE
-    INSERT INTO service_history(car_id, tech_id, cost, start_date, end_date) VALUES (NEW.car_id, NEW.tech_id, NEW.cost, NEW.start_date, NEW.end_date);
+    -- We select the id of the car based on plate number
+    SELECT id INTO latest_car_id
+    FROM car_warehouse WHERE plate = NEW.plate;
+
+    -- We insert the data in the service_history table
+    INSERT INTO service_history(car_id, tech_id, cost, start_date, end_date) VALUES (latest_car_id, NEW.tech_id, NEW.cost, NEW.start_date, NEW.end_date);
+
   END IF;
   RETURN NEW;
 END;
 $BODY$
 LANGUAGE 'plpgsql';
 
-DROP TRIGGER IF EXISTS carExists2 ON temp_car_service;
-CREATE TRIGGER carExists2
+-- Trigger creation
+DROP TRIGGER IF EXISTS carExists ON temp_car_service;
+CREATE TRIGGER carExists
   BEFORE INSERT ON temp_car_service
   FOR EACH ROW
-  EXECUTE PROCEDURE carExists2();
+  EXECUTE PROCEDURE carExists();
+
+-- Dummy data for testing
+INSERT INTO temp_car_service(first_name, last_name, afm, email, phone,
+                             plate, make_id, model_id, manufacturing_date,
+                             tech_id, cost, start_date, end_date)
+VALUES ('Panos', 'Ioannidis', 00112233, '[email protected]', '2299066795',
+        ROW('AEK', '2172'), 2, 22, 1999,
+        11, 999.99, now(), null);
 
+INSERT INTO temp_car_service(first_name, last_name, afm, email, phone,
+                             plate, make_id, model_id, manufacturing_date,
+                             tech_id, cost, start_date, end_date)
+VALUES ('SAKIS', 'NIKAS', 22112233, '[email protected]', '0909888887',
+        ROW('PAO', '1234'), 3, 33, 2000,
+        3, 100.99, now(), null);
 
-INSERT INTO temp_car_service(owner_id, plate, make_id, model_id, manufacturing_date, car_id, tech_id, cost, start_date, end_date)
-VALUES (274, ROW('AEK', '2172'), 2, 22, 1999, 47799, 11, 999.99, now(), null);
+-- This car exist
+INSERT INTO temp_car_service(first_name, last_name, afm, email, phone,
+                             plate, make_id, model_id, manufacturing_date,
+                             tech_id, cost, start_date, end_date)
+VALUES ('Thanos', 'Paravantis', 99887766, '[email protected]', '0987654321',
+        ROW('LTS','6048'), 2, 22, 1999,
+        11, 999.99, now(), null);
+-- end dummy data