diff --git a/Assignments/Assignment4/src/privilege.sql b/Assignments/Assignment4/src/privilege.sql
new file mode 100644
index 0000000..e1fbdd5
--- /dev/null
+++ b/Assignments/Assignment4/src/privilege.sql
@@ -0,0 +1,35 @@
+DROP USER 'ticketAgent'@'localhost';
+DROP USER 'stationManager'@'localhost';
+DROP USER 'adminUser'@'localhost';
+
+FLUSH PRIVILEGES;
+
+CREATE USER 'ticketAgent'@'localhost' IDENTIFIED BY 'password123';
+CREATE USER 'stationManager'@'localhost' IDENTIFIED BY 'password123';
+CREATE USER 'adminUser'@'localhost' IDENTIFIED BY 'password123';
+
+
+GRANT SELECT, INSERT ON DBLab.Tickets TO 'ticketAgent'@'localhost';
+GRANT ALL PRIVILEGES ON DBLab.Stations TO 'stationManager'@'localhost';
+GRANT SELECT, INSERT, UPDATE, DELETE ON DBLab.* TO 'adminUser'@'localhost';
+
+
+REVOKE INSERT ON DBLab.Tickets FROM 'ticketAgent'@'localhost';
+
+GRANT SELECT(Price) ON DBLab.Tickets TO 'ticketAgent'@'localhost';
+GRANT UPDATE(Name, City) ON DBLab.Stations TO 'stationManager'@'localhost';
+
+CREATE ROLE 'ticketRole';
+CREATE ROLE 'stationRole';
+
+
+GRANT SELECT, INSERT ON DBLab.Tickets TO 'ticketRole';
+GRANT SELECT, UPDATE ON DBLab.Stations TO 'stationRole';
+
+
+GRANT 'ticketRole' TO 'ticketAgent'@'localhost';
+GRANT 'stationRole' TO 'stationManager'@'localhost';
+
+REVOKE 'ticketRole' FROM 'ticketAgent'@'localhost';
+
+FLUSH PRIVILEGES;
diff --git a/Assignments/Assignment4/src/view_test.sql b/Assignments/Assignment4/src/view_test.sql
new file mode 100644
index 0000000..baf10c5
--- /dev/null
+++ b/Assignments/Assignment4/src/view_test.sql
@@ -0,0 +1,59 @@
+DROP VIEW
+IF
+	EXISTS v_TrainRoutes;
+DROP VIEW
+IF
+	EXISTS v_StayTimes;
+DROP VIEW
+IF
+	EXISTS v_TrainStationCounts;
+CREATE VIEW v_TrainRoutes AS SELECT
+ID AS TrainID,
+StationID_start,
+StationID_arrive 
+FROM
+	Trains;
+CREATE VIEW v_StayTimes AS SELECT
+TrainID,
+StationID,
+arrive_time,
+leave_time,
+TIMEDIFF( leave_time, arrive_time ) AS StayDuration 
+FROM
+	Passbys;
+CREATE VIEW v_TrainStationCounts AS SELECT
+TrainID,
+COUNT( StationID ) AS StationCount 
+FROM
+	Passbys 
+GROUP BY
+	TrainID;
+SELECT
+	* 
+FROM
+	v_StayTimes 
+WHERE
+	TrainID = 'G103';
+UPDATE v_StayTimes 
+SET StationID = 3 
+WHERE
+	TrainID = 'G103' 
+	AND arrive_time = '2024-03-28 07:13:00';
+SELECT
+	* 
+FROM
+	v_StayTimes 
+WHERE
+	TrainID = 'G103';
+DELETE 
+FROM
+	v_StayTimes 
+WHERE
+	TrainID = 'G103' 
+	AND arrive_time = '2024-03-28 07:13:00';
+SELECT
+	* 
+FROM
+	v_StayTimes 
+WHERE
+	TrainID = 'G103';
\ No newline at end of file