Razan week3

week-1/mandatory/2-classes-db/task.md

@@ -7,9 +7,18 @@ Below you will find a set of tasks for you to complete to consolidate and extend
 To submit this homework write the correct commands for each question here:
 
 ```sql
-
-
-```
+1- select * from rooms where rate >100;
+2-select * from reservations where  checkin_date between '2020-09-01' and '2020-09-30' and  checkout_date - checkin_date >3;
+3-select * from customers where city like 'M%';
+4-insert into room_types( room_type, def_rate) values ('PENTHOUSE', 185.00);
+5-insert into rooms( room_no, room_type, rate) values (501,'PENTHOUSE', 185.00), (502,'PENTHOUSE', 185.00);
+6-insert into rooms( room_no, room_type, rate) values (503,'PREMIER PLUS', 143.00);
+7- select count(room_no)
+ from reservations where checkin_date between '2020-08-01'and '2020-08-31'
+ 8- select sum(checkout_date - checkin_date) from reservations where room_no between 201 and 299;
+ 9- select count(*), sum(total), avg(total) from invoices where total >300;
+ 10- select sum(checkout_date - checkin_date) from reservations group by room_no/100 ;
+ ```
 
 When you have finished all of the questions - open a pull request with your answers to the `Databases-Homework` repository.
 

week-2/mandatory/2-ecommerce-db/task.md

@@ -33,18 +33,62 @@ Open the file `cyf_ecommerce.sql` in VSCode and examine the SQL code. Take a pie
 ## Task
 
 Once you understand the database that you are going to work with, solve the following challenge by writing SQL queries using everything you learned about SQL:
-
 1. Retrieve all the customers' names and addresses who live in the United States
+select name, address from customers where country ='United States';
+
 2. Retrieve all the customers in ascending name sequence
+select * from customers order by name ;
+
 3. Retrieve all the products whose name contains the word `socks`
+select * from products where product_name like '%socks%';
+
 4. Retrieve all the products which cost more than 100 showing product id, name, unit price and supplier id.
+select a.prod_id, p.product_name, a.unit_price, a.supp_id from products p join product_availability a on (a.prod_id = p.id) where a.unit_price >100 ;
+
 5. Retrieve the 5 most expensive products
+select * from product_availability order by unit_price DESC limit 5;
+
 6. Retrieve all the products with their corresponding suppliers. The result should only contain the columns `product_name`, `unit_price` and `supplier_name`
+select p.product_name, a.unit_price, s.supplier_name from products p join product_availability a on (a.prod_id = p.id) join suppliers s on (a.supp_id = s.id) ;
+
 7. Retrieve all the products sold by suppliers based in the United Kingdom. The result should only contain the columns `product_name` and `supplier_name`.
+select p.product_name, s.supplier_name from products p join product_availability a on(a.prod_id = p.id)  join suppliers s on (a.supp_id = s.id) where s.country = 'United Kingdom';
+
 8. Retrieve all orders, including order items, from customer ID `1`. Include order id, reference, date and total cost (calculated as quantity * unit price).
+
+select o.order_reference, o.order_date from  orders o join order_items i on (i.order_id = o.id)  join product_availability a on (a.prod_id = i.product_id) where o.customer_id = 1;  
+////////////I don't understand what they exactly want from this question ////////////////
+
 9. Retrieve all orders, including order items, from customer named `Hope Crosby`
+select o.* from orders o join customers c on (o. customer_id = c.id) where c.name = 'Hope Crosby';
+////// what do yo mean by including order items ////////////////////////////
+
 10. Retrieve all the products in the order `ORD006`. The result should only contain the columns `product_name`, `unit_price` and `quantity`.
+select p.product_name , a.unit_price, i.quantity from  orders o join order_items i on(i.order_id = o.id) join product_availability a on (i.supplier_id = a.supp_id) join products p on (p.id = a. prod_id)
+where o.order_reference = 'ORD006';
+
 11. Retrieve all the products with their supplier for all orders of all customers. The result should only contain the columns `name` (from customer), `order_reference`, `order_date`, `product_name`, `supplier_name` and `quantity`.
+select c.name, o.order_reference, o.order_date, s.supplier_name , i.quantity 
+from customers c join 
+orders o on(c.id= o.customer_id) join
+ order_items i on (o.id = i. order_id) join
+   products p on (i.product_id = p.id) join
+  suppliers s on (s.id =i.supplier_id);
+
 12. Retrieve the names of all customers who bought a product from a supplier based in China.
+select c.name from customers c join orders o on(c.id= o.customer_id) join
+ order_items i on (o.id = i. order_id) join
+ suppliers s on (s.id =i.supplier_id)
+ where s.country = 'China';
+
+
 13. List all orders giving customer name, order reference, order date and order total amount (quantity * unit price) in descending order of total.
+select c.name, o.order_reference, o.order_date, sum (quantity * unit_price) as total
+ from customers c join orders o on(c.id= o.customer_id) join 
+ order_items i on (o.id = i. order_id) join
+ product_availability a on (i.supplier_id = a.supp_id)
+ group by c.name, o.order_reference, o.order_date 
+  ORDER BY totaL DESC ;
+
+
 

week-3/cyf-hotels-api/.gitignore

@@ -0,0 +1 @@
+node_modules