diff --git a/docs/Session04/Lecture.pdf b/docs/Session04/Lecture.pdf
index dee13b44..cb92705a 100644
Binary files a/docs/Session04/Lecture.pdf and b/docs/Session04/Lecture.pdf differ
diff --git a/docs/Session04/Lecture.sql b/docs/Session04/Lecture.sql
index cde50512..f102bd49 100644
--- a/docs/Session04/Lecture.sql
+++ b/docs/Session04/Lecture.sql
@@ -1,7 +1,10 @@
+# Use the database
 use comp353lab;
 
+# drop the target tables if exists
 drop table if exists customers, orders;
 
+# Creating of the tables + Insertion of the date to them
 create table customers(
     id int primary key auto_increment,
     first_name varchar(50),
@@ -15,6 +18,7 @@ create table customers(
 insert into customers(first_name, last_name, email, password, country, balance) values
                         ('Omid Reza', 'Heidari', 'omid.orh@gmail.com', 'password1', 'Iran', 2000),
                         ('Ali', 'Amiri', 'ali@gmail.com', 'password2', 'Canada', 3000),
+                        ('Ali', 'Ahmad', 'ali.ahmad@gmail.com', 'password2', 'Iraq', 4500),
                         ('John', 'Nash', 'nash@gmail.com', 'password3', 'Denmark', 1400),
                         ('Pari', 'Amin', 'pr.am@gmail.com', 'password4', 'Iran', 4200),
                         ('David', 'Ahmad', 'dmp.mmd@gmail.com', 'password5', 'Canada', 300);
@@ -37,45 +41,72 @@ insert into orders(customer_id, amount, created_at, ship_to)
                     (2, 500, '1999-02-02 22:00:00.000000', 'Iran'),
                     (1, 100, '2002-02-02 09:00:00.000000', 'Denmark');
 
+# Eliminate all of the customer with lower balance than 1500
 delete from customers
 where customers.balance<1500;
 
 
+# Update all of the Customers with country of Denmark to Turkey
 update customers
 set customers.country = 'Turkey'
 where customers.country = 'Denmark';
 
-select *
+# See all of the customers
+select customers.id, customers.country
 from customers;
 
-select *
+# Fetch all of the order with id of 1, 3, or 6
+select orders.id, orders.amount, orders.ship_to
 from orders
 where id in (1, 3, 6);
 
+# Alternative way to implement the above command
 select *
 from orders
 where id=1 or id=3 or id=6;
 
+# Fetch all of the countries (orders and customers tables)
 select customers.country
 from customers
 union
 select orders.ship_to
 from orders;
 
-select orders.amount
+# Fetch all of the order with amount in range of 350 and 550
+select orders.id, orders.amount
 from orders
 where amount between 350 and 550;
 
 
-select *
+# Like command (with wildcard)
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like '%da';
+
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like 'Ir%';
+
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like 'Ir_n';
+
+# Like command (without wildcard)
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like 'Canada';
+
+# See all of the customers
+select customers.id, customers.country, customers.first_name, customers.last_name
 from customers;
 
-select *
+# Set limit
+select customers.id, customers.country, customers.first_name, customers.last_name
 from customers
 limit 2;
 
-select *
+# Set Limit with offset
+select customers.id, customers.country, customers.first_name, customers.last_name
 from customers
 limit 2
 offset 1;
-
diff --git a/static/Session04/Lecture.pdf b/static/Session04/Lecture.pdf
index dee13b44..cb92705a 100644
Binary files a/static/Session04/Lecture.pdf and b/static/Session04/Lecture.pdf differ
diff --git a/static/Session04/Lecture.sql b/static/Session04/Lecture.sql
index 76d8c5fa..f102bd49 100644
--- a/static/Session04/Lecture.sql
+++ b/static/Session04/Lecture.sql
@@ -18,6 +18,7 @@ create table customers(
 insert into customers(first_name, last_name, email, password, country, balance) values
                         ('Omid Reza', 'Heidari', 'omid.orh@gmail.com', 'password1', 'Iran', 2000),
                         ('Ali', 'Amiri', 'ali@gmail.com', 'password2', 'Canada', 3000),
+                        ('Ali', 'Ahmad', 'ali.ahmad@gmail.com', 'password2', 'Iraq', 4500),
                         ('John', 'Nash', 'nash@gmail.com', 'password3', 'Denmark', 1400),
                         ('Pari', 'Amin', 'pr.am@gmail.com', 'password4', 'Iran', 4200),
                         ('David', 'Ahmad', 'dmp.mmd@gmail.com', 'password5', 'Canada', 300);
@@ -76,6 +77,25 @@ select orders.id, orders.amount
 from orders
 where amount between 350 and 550;
 
+
+# Like command (with wildcard)
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like '%da';
+
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like 'Ir%';
+
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like 'Ir_n';
+
+# Like command (without wildcard)
+select customers.id, customers.first_name, customers.last_name ,customers.country
+from customers
+where country like 'Canada';
+
 # See all of the customers
 select customers.id, customers.country, customers.first_name, customers.last_name
 from customers;
@@ -90,6 +110,3 @@ select customers.id, customers.country, customers.first_name, customers.last_nam
 from customers
 limit 2
 offset 1;
-
-
-