diff --git a/Trigger.sql b/Trigger.sql
new file mode 100644
index 0000000..22b88a6
--- /dev/null
+++ b/Trigger.sql
@@ -0,0 +1,74 @@
+--This trigger sets the default value for the username column as "Sornaly" before inserting a new row into the userlist table.
+
+CREATE OR REPLACE TRIGGER trg_userlist_insert
+BEFORE INSERT ON userlist
+FOR EACH ROW
+BEGIN
+    IF :NEW.username IS NULL THEN
+        :NEW.username := 'Sornaly';
+    END IF;
+END;
+/
+
+
+
+--This trigger displays a message indicating that a product's information has been updated whenever a row is updated in the products table.
+
+CREATE OR REPLACE TRIGGER trg_products_update
+AFTER UPDATE ON product
+FOR EACH ROW
+BEGIN
+    DBMS_OUTPUT.PUT_LINE('Product information is updated: ' || :NEW.product_name);
+END;
+/
+
+
+--This trigger prevents the deletion of a product if their created_at is below '12-05-23' and raises an exception.
+
+
+CREATE OR REPLACE TRIGGER trg_product_delete
+BEFORE DELETE ON product_name
+FOR EACH ROW
+BEGIN
+    IF :OLD.created_at < '12-0-23' THEN
+        RAISE_APPLICATION_ERROR('12-05-23', 'Cannot delete product. you have it.');
+    END IF;
+END;
+/
+
+
+
+-- This trigger deletes all products from the products table that belong to the product_category being deleted.
+
+
+CREATE OR REPLACE TRIGGER trg_product_category_delete
+AFTER DELETE ON product_category
+FOR EACH ROW
+BEGIN
+    DELETE FROM products WHERE category_id = :OLD.category_id;
+END;
+/
+
+
+
+--This trigger deletes all orders records of a user when that user is deleted.
+
+
+CREATE OR REPLACE TRIGGER trg_order_details_delete
+AFTER DELETE ON userlist
+FOR EACH ROW
+BEGIN
+    DELETE FROM order_details WHERE id = :OLD.id;
+END;
+/
+
+select * from user_triggers;
+drop trigger  trg_order_details_delete;
+drop trigger trg_product_category_delete;
+drop trigger trg_product_delete;
+drop trigger trg_userlist_insert;
+
+
+
+
+
diff --git a/ddl.sql b/ddl.sql
new file mode 100644
index 0000000..80cc907
--- /dev/null
+++ b/ddl.sql
@@ -0,0 +1,29 @@
+alter table product_category add description number(10);
+
+alter table product_category modify description varchar(20);
+
+alter table product_category rename column description to descrip;
+
+alter table products add availability number(20);
+
+alter table products modify availability varchar(20);
+
+alter table products rename column availability to status;
+
+alter table userlist add address varchar(10);
+
+alter table userlist modify address varchar(20);
+
+alter table userlist rename column address to location;
+
+alter table user_payment add payment_status number(20);
+
+alter table user_payment modify payment_status varchar(10);
+
+alter table user_payment rename column payment_status to payment;
+
+alter table order_detail add order_status number(10);
+
+alter table order_detail modify order_status varchar(10);
+
+alter table order_detail rename column order_status to order_;
\ No newline at end of file
diff --git a/dml.sql b/dml.sql
new file mode 100644
index 0000000..47f17d2
--- /dev/null
+++ b/dml.sql
@@ -0,0 +1,96 @@
+---DATA INSERT---
+
+insert into product_category(category_id,category_name,created_at,modified_at) values (100,'Laptop','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (101,'Phone','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (102,'Keyboard','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (103,'Mouse','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (104,'Headphone','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (105,'speaker','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (106,'smartwatch','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (107,'Camera','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (108,'Printer','01-02-22','02-12-22');
+insert into product_category(category_id,category_name,created_at,modified_at) values (109,'TV','01-02-22','02-12-22');
+
+
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (200,'Laptop','HP',100,62000,5000,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (201,'Phone','Xiomi',101,25000,5000,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (202,'Keyboard','Havit',102,7000,0,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (203,'Mouse','Legitech',103,1800,300,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (204,'Headphone','Boat',104,2000,200,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (205,'Speaker','Boat',105,2200,200,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (206,'smartwatch','Samsung',106,7000,500,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (207,'Camera','Canon',107,6200,10000,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (208,'Printer','Canon',108,15000,3000,'01-01-23','01-05-23');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at) values (209,'TV','Sharp',109,62000,1200,'01-01-23','01-05-23');
+
+
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1000,'Sornaly','error','Sadia','Afrin',01726632220,200,'Laptop','01-02-23','05-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1001,'Sabnaj','error1','Sabnaj','Akter',01777258450,201,'Phone','02-02-23','05-06-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1002,'Shama','error2','Farhatun','Shama',01726632221,202,'Keyboard','05-02-23','09-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1003,'Arpita','error3','Arpita','Kundu',01726632222,200,'Laptop','09-02-23','01-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1004,'Deya','error4','Lamisa','Binte',01726632223,204,'Headphone','23-02-23','03-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1005,'Raha','error5','Rubaiya','Raktin',01726632224,205,'Speaker','11-02-23','06-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1006,'Subah','error6','Subah','Noshin',01726632225,200,'Laptop','17-02-23','05-07-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1007,'Mahila','error7','Mahila','Mohiuddin',01726632226,207,'Camera','14-02-23','02-09-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1008,'Shongi','error8','Taslima','Jannat',01726632227,208,'Printer','09-02-23','05-08-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1009,'Mridula','error9','Safwada','Prodhan',01726632228,200,'Laptop','01-02-23','05-01-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1010,'Sornaly','error','Sadia','Afrin',01726632220,200,'Laptop','01-02-23','05-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1011,'Sornaly','error','Sadia','Afrin',01726632220,202,'Keyboard','01-02-23','05-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1012,'Sornaly','error','Sadia','Afrin',01726632220,203,'Speaker','01-02-23','05-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1013,'Sornaly','error','Sadia','Afrin',01726632220,204,'Headphone','01-02-23','05-05-23');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at) values (1014,'Sornaly','error','Sadia','Afrin',01726632220,209,'TV','01-02-23','05-05-23');
+
+
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3000,1000,'COD','NULL',1234567,'20-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3001,1001,'Agent','BKash',01726632220,'21-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3002,1002,'COD','NULL',12345234,'20-09-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3003,1003,'Agent','Rocket',1234567,'20-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3004,1004,'COD','NULL',01726632222,'20-09-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3005,1005,'Agent','Nogod',01726632223,'20-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3006,1006,'COD','NULL',1234567,'20-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3007,1007,'COD','NULL',1234567,'20-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3008,1008,'Agent','BKash',01726632227,'20-08-23');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry) values (3009,1009,'COD','NULL',1234568,'20-08-23');
+
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4000,1000,620000,2,3000,'05-02-23','06-02-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4001,1001,820000,1,3001,'05-03-23','06-12-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4002,1002,420000,7,3002,'05-01-23','06-12-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4003,1003,620000,2,3003,'05-04-23','06-07-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4004,1004,920000,1,3004,'05-05-23','06-02-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4005,1005,1220000,2,3005,'05-08-23','06-05-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4006,1006,670000,3,3006,'05-12-23','06-04-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4007,1007,640000,1,3007,'05-03-23','06-12-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4008,1008,600000,2,3008,'05-07-23','06-11-23');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at) values (4009,1009,600000,1,3009,'05-08-23','06-10-23');
+
+
+
+---COMMANDS---
+set pagesize 550
+set linesize 550
+
+select table_name from user_tables;
+
+select * from product_category;
+select * from products;
+select * from userlist;
+select * from user_payment;
+select * from order_detail;
+
+select * from product_category where category_id>105;
+select * from products where price>=5000;
+select * from userlist where username='Sornaly';
+select * from user_payment where provider='BKash';
+select * from order_detail where total_amount>=50000;
+select * from order_detail where quantity>2;
+
+select username from userlist where product_name=(select product_name from products where product_id=200);
+select username from userlist where product_name=(select product_name from products where product_id=202);
+
+update userlist set username='me_error' where username='Sornaly' and product_name='Laptop';
+select * from userlist;
+---update userlist set username='me_error' where username='Sornaly' except product_name='Speaker';
+---select * from userlist;
+
+delete from userlist where username='Sornaly' and product_name='Speaker';
+select * from userlist; 
\ No newline at end of file
diff --git a/dml2.sql b/dml2.sql
new file mode 100644
index 0000000..35b3d5e
--- /dev/null
+++ b/dml2.sql
@@ -0,0 +1,96 @@
+---DATA INSERT---
+
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (100,'Laptop','01-02-22','02-12-22','For Students');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (101,'Phone','01-02-22','02-12-22','Budget-friendly');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (102,'Keyboard','01-02-22','02-12-22','RGB');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (103,'Mouse','01-02-22','02-12-22','RGB');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (104,'Headphone','01-02-22','02-12-22','Noise cancellation');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (105,'Speaker','01-02-22','02-12-22',' ');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (106,'Smartwatch','01-02-22','02-12-22',' ');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (107,'Camera','01-02-22','02-12-22',' ');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (108,'Printer','01-02-22','02-12-22','Mini');
+insert into product_category(category_id,category_name,created_at,modified_at,descrip) values (109,'TV','01-02-22','02-12-22','Smart-TV');
+
+
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (200,'Laptop','HP',100,62000,5000,'01-01-23','01-05-23','available');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (201,'Phone','Xiomi',101,25000,5000,'01-01-23','01-05-23','available');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (202,'Keyboard','Havit',102,7000,0,'01-01-23','01-05-23','Null');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (203,'Mouse','Legitech',103,1800,300,'01-01-23','01-05-23','available');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (204,'Headphone','Boat',104,2000,200,'01-01-23','01-05-23','Null');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (205,'Speaker','Boat',105,2200,200,'01-01-23','01-05-23','available');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (206,'smartwatch','Samsung',106,7000,500,'01-01-23','01-05-23','Null');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (207,'Camera','Canon',107,62000,10000,'01-01-23','01-05-23','Null');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (208,'Printer','Canon',108,15000,3000,'01-01-23','01-05-23','available');
+insert into products(product_id,product_name,description,category_id,price,discount,created_at,modified_at,status) values (209,'TV','Sharp',109,62000,1200,'01-01-23','01-05-23','available');
+
+
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1000,'Sornaly','error','Sadia','Afrin',01726632220,200,'Laptop',01-02-23','05-05-23','Mymensingh');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1001,'Sabnaj','error1','Sabnaj','Akter',01777258450,201,'Phone',02-02-23','05-06-23','Dhaka');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1002,'Shama','error2','Farhatun','Shama',01726632221,202,'Keyboard',05-02-23','09-05-23','Chittagong');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1003,'Arpita','error3','Arpita','Kundu',01726632222,200,'Laptop','09-02-23','01-05-23','Khulna');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1004,'Deya','error4','Lamisa','Binte',01726632223,204,'Headphone',23-02-23','03-05-23','Sylhet');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1005,'Raha','error5','Rubaiya','Raktin',01726632224,205,'Speaker','11-02-23','06-05-23','Rajshahi');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1006,'Subah','error6','Subah','Noshin',01726632225,200,'Laptop','17-02-23','05-07-23','Narsingdi');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values(1007,'Mahila','error7','Mahila','Mohiuddin',01726632226,207,'Camera',14-02-23','02-09-23','Foridpur');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1008,'Shongi','error8','Taslima','Jannat',01726632227,208,'Printer','09-02-23','05-08-23','Bogra');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1009,'Mridula','error9','Safwada','Prodhan',01726632228,200,'Laptop','01-02-23','05-01-23','Cox's Bazar');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1010,'Sornaly','error','Sadia','Afrin',01726632220,200,'Laptop','01-02-23','05-05-23','Joypurhat');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1011,'Sornaly','error','Sadia','Afrin',01726632220,202,'Keyboard','01-02-23','05-05-23','Rangpur');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1012,'Sornaly','error','Sadia','Afrin',01726632220,203,'Speaker','01-02-23','05-05-23','Cumilla');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1013,'Sornaly','error','Sadia','Afrin',01726632220,204,'Headphone','01-02-23','05-05-23','Barisal');
+insert into userlist(id,username,password,first_name,last_name,phone,product_id,product_name,create_at,modified_at,location) values (1014,'Sornaly','error','Sadia','Afrin',01726632220,209,'TV','01-02-23','05-05-23','Jossore');
+
+
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3000,1000,'COD','NULL',1234567,'20-08-23','Done');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3001,1001,'Agent','BKash',01726632220,'21-08-23','Pending');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3002,1002,'COD','NULL',12345234,'20-09-23','Done');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3003,1003,'Agent','Rocket',1234567,'20-08-23','Done');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3004,1004,'COD','NULL',01726632222,'20-09-23','Pending');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3005,1005,'Agent','Nogod',01726632223,'20-08-23','Pending');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3006,1006,'COD','NULL',1234567,'20-08-23','Done');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3007,1007,'COD','NULL',1234567,'20-08-23','Pending');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3008,1008,'Agent','BKash',01726632227,'20-08-23','Done');
+insert into user_payment(user_payment_id,id,payment_type,provider,account,expiry,payment) values (3009,1009,'COD','NULL',1234568,'20-08-23','Done');
+
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4000,1000,620000,2,3000,'05-02-23','06-02-23','Pending');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4001,1001,820000,1,3001,'05-03-23','06-12-23','Delivered');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4002,1002,420000,7,3002,'05-01-23','06-12-23','Delivered');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4003,1003,620000,2,3003,'05-04-23','06-07-23','Pending');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4004,1004,920000,1,3004,'05-05-23','06-02-23','Delivered');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4005,1005,1220000,2,3005,'05-08-23','06-05-23','Pending');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4006,1006,670000,3,3006,'05-12-23','06-04-23','Delivered');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4007,1007,640000,1,3007,'05-03-23','06-12-23','Pending');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4008,1008,600000,2,3008,'05-07-23','06-11-23','Delivered');
+insert into order_detail(order_id,id,total_amount,quantity,user_payment_id,created_at,modified_at,order_) values (4009,1009,600000,1,3009,'05-08-23','06-10-23','Delivered');
+
+
+
+---COMANDS---
+set pagesize 550
+set linesize 550
+
+select table_name from user_tables;
+
+select * from product_category;
+select * from products;
+select * from userlist;
+select * from user_payment;
+select * from order_detail;
+
+select * from product_category where category_id>105;
+select * from products where price>=5000;
+select * from userlist where username='Sornaly';
+select * from user_payment where provider='BKash';
+select * from order_detail where total_amount>=50000;
+select * from order_detail where quantity>2;
+
+select username from userlist where product_name=(select product_name from products where product_id=200);
+select username from userlist where product_name=(select product_name from products where product_id=202);
+
+update userlist set username='me_error' where username='Sornaly' and product_name='Laptop';
+select * from userlist;
+---update userlist set username='me_error' where username='Sornaly' except product_name='Speaker';
+---select * from userlist;
+
+delete from userlist where username='Sornaly' and product_name='Speaker';
+select * from userlist; \
\ No newline at end of file
diff --git a/pl_sql.sql b/pl_sql.sql
new file mode 100644
index 0000000..76df72a
--- /dev/null
+++ b/pl_sql.sql
@@ -0,0 +1,155 @@
+---see customer id,name,first_name,last_name from userlist table---
+
+set SERVEROUTPUT on
+
+declare 
+userid userlist.id%type;
+user_name userlist.username%type;
+fname userlist.first_name%type;
+lname userlist.last_name%type;
+
+begin
+select id,username,first_name,last_name into userid,user_name,fname,lname from userlist where id=1002;
+dbms_output.put_line('userid:' || userid ||',username:'|| user_name || ',first name:'|| fname || ',last name:' || lname);
+end;
+/
+
+---see arpita's info from userlist----
+set SERVEROUTPUT on
+
+declare 
+userid userlist.id%type;
+user_name userlist.username%type;
+fname userlist.first_name%type;
+lname userlist.last_name%type;
+
+begin
+select id,username,first_name,last_name into userid,user_name,fname,lname from userlist where username='Arpita';
+dbms_output.put_line('userid:' || userid ||',username:'|| user_name || ',first name:'|| fname || ',last name:' || lname);
+end;
+/
+
+
+set serveroutput on
+declare 
+products_row products%rowtype;
+begin
+select product_id,product_name,description,category_id,price,discount,created_at,modified_at into products_row.product_id,products_row.product_name,products_row.description,products_row.category_id,products_row.price,products_row.discount,products_row.created_at,products_row.modified_at from products where product_id=200;
+end;
+/
+
+---show everything using cursor from products table---
+  ---count product row---
+set serveroutput on
+declare 
+cursor product_cursor is
+select * from products;
+products_row products%rowtype;
+begin
+open product_cursor;
+fetch product_cursor into products_row.product_id,products_row.product_name,products_row.description,products_row.category_id,products_row.price,products_row.discount,products_row.created_at,products_row.modified_at;
+while product_cursor%found 
+loop
+dbms_output.put_line('product id: '||products_row.product_id|| ', product name: '||products_row.product_name||',Description: '||products_row.description||',category id: '||products_row.category_id||',price: '||products_row.price||',discount: '||products_row.discount||',created at'||products_row.created_at||',modified at'||products_row.modified_at);
+dbms_output.put_line('Row count: '|| product_cursor%rowcount);
+fetch product_cursor into products_row.product_id,products_row.product_name,products_row.description,products_row.category_id,products_row.price,products_row.discount,products_row.created_at,products_row.modified_at;
+end loop;
+close product_cursor;
+end;
+/
+
+---array,if,else,loop use---
+
+set serveroutput on
+declare
+counter number:=1;
+pro_name products.product_name%type;
+type namearray is varray(5) of products.pro_name%type;
+a_name namearray:=namearray('laptop','phone','mouse','keyboard','watch');
+
+begin
+counter:=1;
+
+for x in 12..16
+loop
+select product_name into pro_name from products where products_id=100000;
+if pro_name='laptop' 
+then 
+dbms_output.put_line(pro_name);
+
+elsif pro_name='phone'
+then 
+dbms_output.put_line(pro_name);
+else
+dbms_output.put_line('other gadgets');
+
+end if;
+
+end loo;
+
+end;
+
+
+---procedure---
+set serveroutput on
+CREATE OR REPLACE PROCEDURE proc2(
+  var1 IN varchar1,
+  var2 OUT VARCHAR2,
+  var3 IN OUT NUMBER
+)
+AS
+  t_show CHAR(30);
+BEGIN
+  t_show := 'From procedure: ';
+  SELECT product_name INTO var2 FROM products WHERE category_id IN (SELECT category_id FROM product_category created_at = var1);
+  var3 := var1 + 1; 
+  DBMS_OUTPUT.PUT_LINE(t_show || var2 || ' is added in list at  ' || var1 || ' and price is  ' || var3);
+END;
+/
+
+
+set serveroutput on
+declare 
+created_date products.created_date%type;
+pro_name products.product_name%type;
+price number;
+begin
+proc2(pro_id,pro_name,price);
+end;
+/
+
+
+---function---
+
+set serveroutput on
+create or replace function fun(var1 in varchar) return varchar AS
+value products.product_name%type;
+begin
+  select product_name into pro_name from products where pro_id=var1; 
+   return value;
+end;
+/
+
+set serveroutput on
+declare 
+value varchar(20);
+begin
+value:=fun(10000);
+end;
+/
+
+  
+---INTRODUCTION---
+
+set SERVEROUTPUT on;
+begin
+dbms_output.put_line('                                                                                                       ');
+dbms_output.put_line('    ');
+dbms_output.put_line('    ');
+dbms_output.put_line('    ');
+dbms_output.put_line('-------------------------------------------------------------------------------------------------------- ');
+dbms_output.put_line('Project Name : Gadget Store Management System');
+dbms_output.put_line('Created by : Sadia Afrin');
+dbms_output.put_line('Roll : 1907037');
+end;
+/
diff --git a/table.sql b/table.sql
new file mode 100644
index 0000000..3281a3f
--- /dev/null
+++ b/table.sql
@@ -0,0 +1,66 @@
+drop table order_detail;
+drop table user_payment;
+drop table userlist;
+drop table products;
+drop table product_category;
+
+
+create table product_category(
+category_id number(10)NOT NULL,
+category_name varchar(10),
+created_at varchar(10),
+modified_at varchar(10),
+primary key(category_id)
+);
+
+create table products(
+product_id number(10) NOT NULL,
+product_name varchar(10),
+description varchar(10),
+category_id number(10) NOT NULL,
+price number(15),
+discount number(15),
+created_at varchar(10),
+modified_at varchar(10),
+primary key(product_id),
+foreign key(category_id) references product_category(category_id)
+);
+
+create table userlist(
+id number(10) NOT NULL,
+username varchar(10) NOT NULL,
+password varchar(10),
+first_name varchar(10),
+last_name varchar(10),
+phone number(11),
+product_id number(10) NOT NULL,
+product_name varchar(10),
+create_at varchar(10),
+modified_at varchar(10),
+primary key(id),
+foreign key(product_id) references products(product_id)
+);
+
+create table user_payment(
+user_payment_id number(10)NOT NULL,
+id number(20) NOT NULL,
+payment_type varchar(20),
+provider varchar(20),
+account number(30),
+expiry varchar(20),
+primary key(user_payment_id),
+foreign key(id)references userlist(id)
+);
+
+create table order_detail(
+order_id number(10)NOT NULL,
+id number(10)NOT NULL,
+total_amount number(15),
+quantity number(10),
+user_payment_id number(10) NOT NULL, 
+created_at varchar(10),
+modified_at varchar(10),
+primary key(order_id),
+foreign key(id) references userlist(id),
+foreign key(user_payment_id) references user_payment(user_payment_id)
+);
\ No newline at end of file