diff --git a/DDL2.sql b/DDL2.sql
new file mode 100644
index 0000000..99d667f
--- /dev/null
+++ b/DDL2.sql
@@ -0,0 +1,76 @@
+-- Drop tables
+
+DROP TABLE ticket_info;
+DROP TABLE flight_details;
+DROP TABLE credit_card_details;
+DROP TABLE flight;
+DROP TABLE passenger;
+
+-- Create tables
+
+CREATE TABLE flight (
+flight_id NUMBER PRIMARY KEY,
+airline_id NUMBER NOT NULL,
+airline_name VARCHAR(50) NOT NULL,
+from_location VARCHAR(50) NOT NULL,
+to_location VARCHAR(50) NOT NULL,
+departure_time VARCHAR(50) NOT NULL,
+arrival_time VARCHAR(50) NOT NULL,
+total_seats NUMBER CHECK (total_seats >= 100 AND total_seats <= 1000)
+);
+
+CREATE TABLE passenger (
+profile_id NUMBER PRIMARY KEY,
+password VARCHAR(50) NOT NULL,
+f_name VARCHAR(50) NOT NULL,
+l_name VARCHAR(50) NOT NULL,
+m_name VARCHAR(20),
+address VARCHAR(50),
+mobile_no VARCHAR(50) NOT NULL UNIQUE,
+email VARCHAR(50) NOT NULL UNIQUE
+);
+
+CREATE TABLE credit_card_details (
+profile_id NUMBER NOT NULL,
+card_number VARCHAR(50) PRIMARY KEY,
+card_type VARCHAR(50) NOT NULL,
+expiration_month VARCHAR(50) NOT NULL,
+expiration_year NUMBER NOT NULL,
+FOREIGN KEY (profile_id) REFERENCES passenger(profile_id)
+);
+
+CREATE TABLE flight_details (
+flight_id NUMBER NOT NULL,
+flight_departure_date DATE,
+price NUMBER NOT NULL CHECK (price >= 1000 AND price <= 100000),
+PRIMARY KEY (flight_id, flight_departure_date),
+FOREIGN KEY (flight_id) REFERENCES flight(flight_id)
+);
+
+CREATE TABLE ticket_info (
+ticket_id NUMBER PRIMARY KEY,
+profile_id NUMBER NOT NULL,
+flight_id NUMBER NOT NULL,
+flight_d_date DATE NOT NULL,
+status VARCHAR(50),
+FOREIGN KEY (flight_id) REFERENCES flight(flight_id),
+FOREIGN KEY (profile_id) REFERENCES passenger(profile_id),
+FOREIGN KEY (flight_id, flight_d_date) REFERENCES flight_details(flight_id, flight_departure_date)
+);
+
+-- Add column in the table
+
+ALTER TABLE flight ADD duration VARCHAR(50);
+
+-- Modify column definition in the table
+
+ALTER TABLE flight MODIFY duration VARCHAR(20);
+
+-- Rename the column name
+
+ALTER TABLE flight RENAME COLUMN total_seats TO seats;
+
+-- Drop the column from table
+
+ALTER TABLE passenger DROP COLUMN m_name;
+ALTER TABLE flight DROP COLUMN duration;
\ No newline at end of file
diff --git a/DML.sql b/DML.sql
new file mode 100644
index 0000000..83c5644
--- /dev/null
+++ b/DML.sql
@@ -0,0 +1,352 @@
+--insert values into tables
+
+
+insert into flight values(1,11,'Novoair','Dhaka','Jessore','10:00 am','11:30 am',200);
+insert into flight values(2,11,'Novoair','Dhaka','Saiadpur','10:00 pm','11:45 pm',200);
+insert into flight values(3,11,'Novoair','Dhaka','Chottogram','1:00 pm','2:30 pm',250);
+insert into flight values(4,12,'US-Bangla','Dhaka','Jessore','11:00 am','12:30 pm',300);
+insert into flight values(5,12,'US-Bangla','Dhaka','Saiadpur','3:00 pm','4:30 pm',300);
+insert into flight values(6,12,'US-Bangla','Dhaka','Chottogram','8:00 pm','9:30 pm',400);
+insert into flight values(7,13,'Biman Bangladesh','Dhaka','Jessore','10:00 am','11:30 am',250);
+insert into flight values(8,13,'Biman Bangladesh','Dhaka','Saiadpur','10:00 am','11:30 am',250);
+insert into flight values(9,13,'Biman Bangladesh','Dhaka','Chottogram','4:00 pm','5:38 pm',250);
+insert into flight values(10,13,'Biman Bangladesh','Dhaka','Sylhet','9:00 pm','11:00 pm',300);
+
+
+
+
+insert into passenger values(111,'ld','lamisa','deya','Jamalpur','01707494817','deya@gmail.com');
+insert into passenger values(112,'ac','anika','chhoa','Jamalpur','01707494818','chhoa@gmail.com');
+insert into passenger values(113,'ak','arpita','kundu','Khulna','01707494819','kundu@gmail.com');
+insert into passenger values(114,'ms','mizan','swapon','Jamalpur','01707494820','swapon@gmail.com');
+insert into passenger values(115,'ss','sadia','sornaly','Mymensingh','01707494821','sornaly@gmail.com');
+insert into passenger values(116,'rr','rubaiya','raha','Rajshahi','01707494822','raha@gmail.com');
+insert into passenger values(117,'jb','jytosna','begum','jamalpur','01707494823','begum@gmail.com');
+insert into passenger values(118,'tz','taslima','zannat','Mymensingh','01707494824','zannat@gmail.com');
+insert into passenger values(119,'tt','tafannum','tareq','chottogram','01707494825','tareq@gmai;.com');
+insert into passenger values(120,'mm','mahila','mohiuddin','Coxs bazar','01707494826','mahila@gmail.com');
+
+
+
+
+insert into credit_card_details values(111,'3141 5926 5643 7890','visa','jnuary',2024);
+insert into credit_card_details values(112,'4141 5926 5643 7890','business','December',2025);
+insert into credit_card_details values(113,'5141 5926 5643 7890','mastercard','june',2026);
+insert into credit_card_details values(114,'6141 5926 5643 7890','visa','december',2024);
+insert into credit_card_details values(115,'7141 5926 5643 7890','business','january',2025);
+insert into credit_card_details values(116,'9141 5926 5643 7890','mastercard','june',2026);
+insert into credit_card_details values(117,'3141 8926 5643 7890','visa','december',2024);
+insert into credit_card_details values(118,'3141 6926 5643 7890','business','january',2025);
+insert into credit_card_details values(119,'3141 1926 5643 7890','mastercard','june',2026);
+insert into credit_card_details values(120,'3141 9926 5643 7890','visa','december',2024);
+
+
+
+
+
+insert into flight_details values(1,date '2023-04-12',4000);
+insert into flight_details values(1,date '2023-04-13',4400);
+insert into flight_details values(1,date '2023-04-14',4500);
+insert into flight_details values(2,date '2023-04-12',5000);
+insert into flight_details values(2,date '2023-04-13',5400);
+insert into flight_details values(2,date '2023-04-14',5500);
+insert into flight_details values(3,date '2023-04-12',6000);
+insert into flight_details values(3,date '2023-04-13',6400);
+insert into flight_details values(3,date '2023-04-14',6500);
+insert into flight_details values(4,date '2023-04-12',4000);
+insert into flight_details values(4,date '2023-04-13',4400);
+insert into flight_details values(4,date '2023-04-14',4500);
+insert into flight_details values(5,date '2023-04-12',5000);
+insert into flight_details values(5,date '2023-04-13',5400);
+insert into flight_details values(5,date '2023-04-14',5500);
+insert into flight_details values(6,date '2023-04-12',6000);
+insert into flight_details values(6,date '2023-04-13',6400);
+insert into flight_details values(6,date '2023-04-14',6500);
+insert into flight_details values(7,date '2023-04-12',4000);
+insert into flight_details values(7,date '2023-04-13',4400);
+insert into flight_details values(7,date '2023-04-14',4500);
+insert into flight_details values(8,date '2023-04-12',5000);
+insert into flight_details values(8,date '2023-04-13',5400);
+insert into flight_details values(8,date '2023-04-14',5500);
+insert into flight_details values(9,date '2023-04-12',6000);
+insert into flight_details values(9,date '2023-04-13',6400);
+insert into flight_details values(9,date '2023-04-14',6500);
+insert into flight_details values(10,date '2023-04-12',4000);
+insert into flight_details values(10,date '2023-04-13',4400);
+insert into flight_details values(10,date '2023-04-14',4500);
+
+
+
+insert into ticket_info values(001,111,1,date '2023-04-12','paid');
+insert into ticket_info values(002,111,2,date '2023-04-12','unpaid');
+insert into ticket_info values(003,111,3,date '2023-04-12','paid');
+insert into ticket_info values(004,112,3,date '2023-04-12','paid');
+insert into ticket_info values(005,112,4,date '2023-04-13','paid');
+insert into ticket_info values(006,112,7,date '2023-04-13','paid');
+insert into ticket_info values(007,113,5,date '2023-04-14','unpaid');
+insert into ticket_info values(008,113,6,date '2023-04-13','paid');
+insert into ticket_info values(009,114,8,date '2023-04-12','paid');
+insert into ticket_info values(010,115,3,date '2023-04-12','unpaid');
+insert into ticket_info values(011,116,5,date '2023-04-14','unpaid');
+insert into ticket_info values(012,117,4,date '2023-04-13','paid');
+insert into ticket_info values(013,118,5,date '2023-04-14','unpaid');
+insert into ticket_info values(014,118,6,date '2023-04-13','paid');
+insert into ticket_info values(015,119,3,date '2023-04-12','paid');
+insert into ticket_info values(016,119,7,date '2023-04-13','paid');
+insert into ticket_info values(017,119,2,date '2023-04-12','unpaid');
+insert into ticket_info values(018,120,8,date '2023-04-12','paid');
+insert into ticket_info values(019,120,8,date '2023-04-12',null);
+
+
+
+
+--show all the entries
+
+
+select * from flight;
+select * from passenger;
+select * from credit_card_details;
+select * from flight_details;
+select * from ticket_info;
+
+
+
+--select multiple row using where condition
+
+
+
+select * from flight where flight_id=2;
+select * from passenger where profile_id=2;
+select * from credit_card_details where card_number='3141 5926 5643 7890';
+select * from flight_details where flight_id=2 and flight_departure_date=date '2023-04-13';
+select * from ticket_info where ticket_id=017;
+select * from flight where seats>100;
+
+
+--select one row using where condition
+
+
+
+select * from flight_details where flight_id=2;
+
+
+--basic select commands
+
+
+select distinct f_name from passenger;
+select all f_name from passenger;
+select flight_id, seats/2 as halfSeats,seats from flight;
+
+
+---cartesian product
+
+
+
+select * from flight a,flight_details b where a.flight_id=b.flight_id;
+
+
+
+--range search
+
+
+
+select * from flight_details where price>3000 and price<5000;
+
+
+--delete all tuples
+
+
+
+--delete from passenger;
+
+
+--delete a single row 
+
+
+delete flight_details where flight_id=1 and flight_departure_date=date'2023-04-12';
+
+
+--string operations
+
+--(first name starts with l or t)
+select f_name from passenger where f_name like 'l%' or f_name like 't%';
+--(airline name has the character a)
+select * from flight where airline_name like '%a%';
+
+
+
+--ordering the display of tuple
+
+
+select * from credit_card_details order by expiration_year;
+select * from passenger order by f_name;
+select * from passenger order by f_name desc;
+
+
+--set operations
+
+
+select * from credit_card_details where expiration_year=2024
+union
+select * from credit_card_details where expiration_year=2023;
+
+select * from credit_card_details where expiration_year=2024
+intersect
+select * from credit_card_details where expiration_month='jnuary';
+
+select * from credit_card_details where expiration_year=2024
+minus
+select * from credit_card_details where expiration_month='jnuary';
+
+
+
+-null values
+
+
+select * from ticket_info where status is null;
+
+
+--aggregate functions
+
+
+select avg(price) as average_price from flight_details;
+select max(price) as maximum_price from flight_details;
+select min(price) as minimum_price from flight_details;
+select sum(seats) as all_seats from flight;
+select count(*) from ticket_info;
+
+
+--agregate Functions – haing cause andgroup by
+
+
+select avg(price),flight_id from flight_details group by flight_id;
+select avg(price),flight_id from flight_details group by flight_id having avg(price)>5000;
+
+
+--nested subqueries
+
+
+select * from ticket_info where (flight_d_date,flight_id )in
+(select flight_departure_date,flight_id from flight_details where flight_id in 
+(select flight_id from flight where airline_id=11));
+
+
+
+--set membership 
+
+
+select f_name from passenger where f_name not in ('lamisa','anika');
+select *  from passenger where f_name in ('lamisa','anika');
+
+
+
+--update
+
+
+
+update flight_details set price=1.03*price where price<=5000;
+update flight set seats=10+seats where seats=200;
+
+
+--join 
+
+
+
+--(natural join)
+select * from passenger natural join credit_card_details;
+select * from flight natural join flight_details where flight_id in(1,2,3);
+
+--(inner join)
+select * from flight join flight_details using(flight_id);
+select * from passenger join credit_card_details using(profile_id);
+
+--(outer join)
+select * from passenger left outer  join credit_card_details using(profile_id);
+select * from passenger right  outer  join credit_card_details using(profile_id);
+select * from passenger full  outer  join credit_card_details using(profile_id);
+select * from flight left outer  join flight_details using(flight_id);
+select * from flight right  outer  join flight_details using(flight_id);
+select * from flight full  outer  join flight_details using(flight_id);
+
+
+
+--view
+
+
+
+create view personal_info as select f_name,l_name,address,mobile_no,email from passenger;
+create view visa_card_details as select * from credit_card_details where card_type='visa';
+select * from personal_info;
+select * from visa_card_details;
+
+--(view from another view)
+create view passenger_details as select f_name,l_name,mobile_no from personal_info;
+
+--(view drop)
+drop view personal_info;
+drop view passenger_details;
+drop view visa_card_details;
+
+
+--with clause
+
+
+
+with max_price(p) as (select max(price) from flight_details)
+select * from flight_details a,max_price b where a.price=b.p;
+
+
+with avg_price(p) as (select avg(price) from flight_details)
+select * from flight_details a,avg_price b where a.price>b.p;
+
+
+
+--"some" and "all" clause
+
+
+
+select * from flight where seats> some(select seats from flight where seats<250);
+select * from flight where seats> all(select seats from flight where seats<250);
+
+
+
+--"exists" and "not exists" clause
+
+
+
+select * from passenger where profile_id>=115 and exists (select * from credit_card_details where card_type='visa');
+select * from passenger where profile_id>=115 and not  exists (select * from credit_card_details where card_type='Master');
+
+
+
+-- show user name
+show user;
+
+-- show the list of tables
+select table_name from user_tables;
+
+-- show all tables and views from the tab
+select * from tab;
+
+-- descriptions of table
+desc passenger;
+desc credit_card_details;
+desc flight;
+desc flight_details;
+desc ticket_info;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/PL.sql b/PL.sql
new file mode 100644
index 0000000..75c4998
--- /dev/null
+++ b/PL.sql
@@ -0,0 +1,264 @@
+-- PL/SQL variable declaration and print value
+SET serveroutput ON
+
+DECLARE
+  id flight_details.flight_id%type;
+  dates flight_details.flight_departure_date%type;
+  price flight_details.price%type;
+BEGIN
+  SELECT flight_id, flight_departure_date, price INTO id, dates, price
+  FROM flight_details
+  WHERE flight_id = 1 AND flight_departure_date = DATE '2023-04-12';
+  
+  dbms_output.put_line('id = ' || id || ', date = ' || dates || ', price = ' || price);
+END;
+/
+
+-- Insert and set default value
+SET serveroutput ON
+
+DECLARE
+  id flight_details.flight_id%type := 1;
+  dates flight_details.flight_departure_date%type := DATE '2023-04-15';
+  price flight_details.price%type := 6000;
+BEGIN
+  INSERT INTO flight_details VALUES (id, dates, price);
+END;
+/
+
+-- %ROWTYPE
+SET serveroutput ON
+
+DECLARE
+  flight flight_details%rowtype;
+BEGIN
+  SELECT flight_id, flight_departure_date, price INTO flight.flight_id, flight.flight_departure_date, flight.price
+  FROM flight_details
+  WHERE flight_id = 1 AND flight_departure_date = DATE '2023-04-12';
+  
+  dbms_output.put_line('id = ' || flight.flight_id || ', date = ' || flight.flight_departure_date || ', price = ' || flight.price);
+END;
+/
+
+-- Insert and set default value using %ROWTYPE
+SET serveroutput ON
+
+DECLARE
+  flight flight_details%rowtype;
+BEGIN
+  flight.flight_id := 2;
+  flight.flight_departure_date := DATE '2023-04-15';
+  flight.price := 5800;
+  INSERT INTO flight_details VALUES flight;
+END;
+/
+
+-- Creating a cursor
+SET serveroutput ON
+
+DECLARE
+  CURSOR pass_cur IS
+    SELECT profile_id, f_name, l_name FROM passenger;
+  p_id passenger.profile_id%type;
+  f_name passenger.f_name%type;
+  l_name passenger.l_name%type;
+BEGIN
+  OPEN pass_cur;
+  FETCH pass_cur INTO p_id, f_name, l_name;
+  
+  WHILE pass_cur%FOUND LOOP
+    dbms_output.put_line(p_id || ' ' || f_name || ' ' || l_name);
+    FETCH pass_cur INTO p_id, f_name, l_name;
+  END LOOP;
+  
+  CLOSE pass_cur;
+END;
+/
+
+-- %ISOPEN, %FOUND, %ROWCOUNT, %NOTFOUND
+SET serveroutput ON
+
+DECLARE
+  CURSOR pass_cur IS
+    SELECT profile_id, f_name, l_name FROM passenger;
+  p_id passenger.profile_id%type;
+  f_name passenger.f_name%type;
+  l_name passenger.l_name%type;
+BEGIN
+  OPEN pass_cur;
+  FETCH pass_cur INTO p_id, f_name, l_name;
+  
+  WHILE pass_cur%FOUND LOOP
+    dbms_output.put_line(p_id || ' ' || f_name || ' ' || l_name);
+    FETCH pass_cur INTO p_id, f_name, l_name;
+  END LOOP;
+  
+  IF (pass_cur%NOTFOUND) THEN
+    dbms_output.put_line('end');
+  ELSE
+    dbms_output.put_line('wrong');
+  END IF;
+  
+  dbms_output.put_line('row ' || pass_cur%ROWCOUNT);
+  CLOSE pass_cur;
+  
+  IF (pass_cur%ISOPEN) THEN
+    dbms_output.put_line('Cursor is open');
+  ELSE
+    dbms_output.put_line('Cursor is closed');
+  END IF;
+END;
+/
+
+-- Procedure with parameter type IN
+CREATE OR REPLACE PROCEDURE proc(id IN NUMBER) IS
+  name passenger.f_name%TYPE;
+BEGIN
+  SELECT f_name INTO name FROM passenger WHERE passenger.profile_id = id;
+  dbms_output.put_line(name);
+END;
+/
+
+SET serveroutput ON
+
+DECLARE 
+  var1 passenger.profile_id%TYPE := 111;
+BEGIN
+  proc(var1);
+END;
+/
+
+-- Procedure with parameter type OUT
+CREATE OR REPLACE PROCEDURE proc(name OUT passenger.f_name%TYPE) IS
+BEGIN
+  SELECT f_name INTO name FROM passenger WHERE passenger.profile_id = 111;
+END;
+/
+
+SET serveroutput ON
+
+DECLARE 
+  name passenger.f_name%TYPE;
+BEGIN
+  proc(name);
+  dbms_output.put_line(name);
+END;
+/
+
+-- Procedure with parameter type IN and OUT
+CREATE OR REPLACE PROCEDURE proc(id IN NUMBER, name OUT passenger.f_name%TYPE) IS
+BEGIN
+  SELECT f_name INTO name FROM passenger WHERE passenger.profile_id = id;
+END;
+/
+
+SET serveroutput ON
+
+DECLARE 
+  name passenger.f_name%TYPE;
+  id passenger.profile_id%TYPE;
+BEGIN
+  id := 111;
+  proc(id, name);
+  dbms_output.put_line(name);
+END;
+/
+
+-- Procedure with no parameters
+CREATE OR REPLACE PROCEDURE proc IS
+  name passenger.f_name%TYPE;
+BEGIN
+  SELECT f_name INTO name FROM passenger WHERE passenger.profile_id = 111;
+  dbms_output.put_line(name);
+END;
+/
+
+SET serveroutput ON
+
+DECLARE 
+BEGIN
+  proc();
+END;
+/
+
+-- Procedure with parameter type IN OUT
+CREATE OR REPLACE PROCEDURE proc(name IN passenger.f_name%TYPE, id IN OUT NUMBER) IS
+  aa NUMBER;
+  b NUMBER;
+BEGIN
+  SELECT id INTO aa FROM passenger WHERE passenger.f_name = name;
+  dbms_output.put_line(aa);
+  b := aa + 10;
+  dbms_output.put_line(b);
+  UPDATE passenger SET profile_id = b WHERE profile_id = aa;
+END;
+/
+
+SET serveroutput ON
+
+DECLARE 
+  name passenger.f_name%TYPE := 'lamisa';
+  id passenger.profile_id%TYPE;
+BEGIN
+  proc(name, id);
+END;
+/
+
+-- Error showing
+SHOW ERRORS PROCEDURE proc;
+
+-- Dropping a procedure
+DROP PROCEDURE proc;
+
+-- Function
+CREATE OR REPLACE FUNCTION fun(idd IN NUMBER)
+RETURN passenger.f_name%TYPE IS
+  f_name passenger.f_name%TYPE;
+BEGIN
+  SELECT f_name INTO f_name FROM passenger WHERE passenger.profile_id = idd;
+  RETURN f_name;
+END;
+/
+
+SET serveroutput ON
+
+DECLARE 
+  id passenger.profile_id%TYPE := 111;
+BEGIN
+  dbms_output.put_line(fun(id));
+END;
+/
+
+-- Error showing
+SHOW ERRORS FUNCTION fun;
+
+-- Dropping a function
+DROP FUNCTION fun;
+
+-- If/Else/Loop
+SET serveroutput ON
+
+DECLARE
+  CURSOR c IS
+    SELECT * FROM flight_details;
+  avrg NUMBER;
+  rec flight_details%ROWTYPE;
+BEGIN
+  OPEN c;
+  FETCH c INTO rec;
+  SELECT AVG(price) INTO avrg FROM flight_details;
+  
+  WHILE c%FOUND LOOP
+    IF rec.price < avrg THEN
+      dbms_output.put_line('Price is low');
+    ELSE
+      dbms_output.put_line('Price is high');
+    END IF;
+    
+    FETCH c INTO rec;
+  END LOOP;
+  
+  CLOSE c;
+END;
+/
+
diff --git a/trigger.sql b/trigger.sql
new file mode 100644
index 0000000..0965839
--- /dev/null
+++ b/trigger.sql
@@ -0,0 +1,42 @@
+-- create a trigger before delete on a table 
+
+SET SERVEROUTPUT ON
+CREATE OR REPLACE TRIGGER trig1
+BEFORE delete ON creadit_card_details
+REFERENCING OLD AS o NEW AS n
+FOR EACH ROW
+BEGIN
+delete from passenger where profile_id=:o.profile_id;
+
+END;
+/
+
+
+
+-- create a trigger after update on a table 
+
+
+SET SERVEROUTPUT ON
+CREATE OR REPLACE TRIGGER trig2
+after update ON flight_details
+REFERENCING OLD AS o NEW AS n
+FOR EACH ROW
+Enable
+BEGIN
+update flight set flight.SEATS=:n.price/100 where flight_id=:n.flight_id;
+END;
+/
+
+-- create a trigger after insert into a table 
+
+
+SET SERVEROUTPUT ON
+CREATE OR REPLACE TRIGGER trig3
+after insert ON flight_details
+REFERENCING OLD AS o NEW AS n
+FOR EACH ROW
+Enable
+BEGIN
+update flight set flight.SEATS=:n.price/100 where flight_id=:n.flight_id;
+END;
+/
\ No newline at end of file