Database week 2

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

@@ -2,11 +2,37 @@
 
 ## Submission
 
-Below you will find a set of tasks for you to complete to consolidate and extend your learning from this week.  You will find it beneficial to complete the reading tasks before attempting some of these.
+Below you will find a set of tasks for you to complete to consolidate and extend your learning from this week. You will find it beneficial to complete the reading tasks before attempting some of these.
 
 To submit this homework write the correct commands for each question here:
 
 ```sql
+1.select * from rooms where rate>=100.00;
+2.select * from reservations where EXTRACT(MONTH from checkin_date)=EXTRACT(MONTH from current_date) and checkout_date-checkin_date>3;
+3.select * from customers where name 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 (502,'PENTHOUSE',185.00);
+5.insert into rooms (room_no,room_type,rate) values (502,'PENTHOUSE',185.00);
+to check what is inserted
+select * from rooms order by room_no DESC LIMIT 10;
+6. insert into rooms (room_no,rate,room_type) values(503 ,143.00,'PREMIER PLUS');
+7. select COUNT(*)  from reservations where EXTRACT(MONTH from checkin_date)=EXTRACT(MONTH from current_date -1);
+8.select COUNT(checkout_date-checkin_date) from reservations where room_no BETWEEN 200 AND 300;
+9. select COUNT(*) as total_no_of_invoices ,AVG(total) as average ,SUM(total) as total from invoices where total>300.00;
+10.
+first-floor
+select sum(checkout_date-checkin_date) as nights_on_first_floor from reservations where room_no between 101 and 199;
+second-floor
+select sum(checkout_date-checkin_date) as nights_on_first_floor from reservations where room_no between 201 and 299;
+third_floor
+select sum(checkout_date-checkin_date) as nights_on_first_floor from reservations where room_no between 201 and 299;
+
+
+
+
+
+
+
 
 
 ```
@@ -18,6 +44,7 @@ When you have finished all of the questions - open a pull request with your answ
 If you haven't completed all the exercises from this lesson then do that first.
 
 ### Tasks
+
 1.  Which rooms have a rate of more than 100.00?
 2.  List the reservations that have a checkin date this month and are for more than three nights.
 3.  List all customers from cities that begin with the letter 'M'.
@@ -32,5 +59,5 @@ Using what you can learn about aggregate functions in the w3schools SQL classes
 
 7.  The hotel manager wishes to know how many rooms were occupied any time during the previous month - find that information.
 8.  Get the total number of nights that customers stayed in rooms on the second floor (rooms 201 - 299).
-9.  How many invoices are for more than £300.00 and what is their grand total and average amount?
-10.  Bonus Question: list the number of nights stay for each floor of the hotel (floor no is the hundreds part of room number, e.g. room **3**12 is on floor **3**)
+9.  How many invoices are for more than £300.00 and what is their grand total and 2average amount?
+10. Bonus Question: list the number of nights stay for each floor of the hotel (floor no is the hundreds part of room number, e.g. room **3**12 is on floor **3**)

week-2/mandatory/2-ecommerce-db/cyf_ecommerce.sql

@@ -48,6 +48,9 @@ CREATE TABLE order_items (
         REFERENCES product_availability (prod_id, supp_id)
 );
 
+
+
+
 INSERT INTO customers (name, address, city, country) VALUES ('Guy Crawford','770-2839 Ligula Road','Paris','France');
 INSERT INTO customers (name, address, city, country) VALUES ('Hope Crosby','P.O. Box 276, 4976 Sit Rd.','Steyr','United Kingdom');
 INSERT INTO customers (name, address, city, country) VALUES ('Britanney Kirkland','P.O. Box 577, 5601 Sem, St.','Little Rock','United Kingdom');

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

@@ -7,9 +7,60 @@ In this homework, you are going to work with an ecommerce database. In this data
 Below you will find a set of tasks for you to complete to set up a database for an e-commerce app.
 
 To submit this homework write the correct commands for each question here:
+
 ```sql
 
 
+1.select name ,address from customers where country='United States';
+2.select name from customers order by name asc;
+3.select * from  products where product_name ilike '%sock%';
+4.select p.product_name ,pa.prod_id ,pa.unit_price,pa.supp_id
+    from products p join  product_availability pa
+    on (p.id=pa.prod_id)
+    where pa.unit_price>100;
+5. select p.id,p.product_name ,pa.unit_price
+        from products p join  product_availability  pa
+        on p.id=pa.prod_id
+        order by unit_price
+         desc limit 5;
+6.select p.product_name ,pa.unit_price, s.supplier_name
+        from products p join suppliers s
+        on p.id=s.id;
+        join product_availability
+        pa on pa.prod_id=p.id;
+7. select p.product_name,s.supplier_name from products p
+        join product_availability pa on p.id=pa.prod_id
+        join suppliers s on s.id=pa.supp_id;
+        where s.country='United Kingdom';
+8.select pa.unit_price ,o.id,o.order_date ,o.order_reference ,o.customer_id,oi.    quantity,pa.unit_price/oi.quantity as total_cost
+        from product_availability
+         pa join orders o on pa.prod_id =o.id
+         join order_items oi  on o.id =oi.id
+         where o.customer_id=1;
+9.select c.name ,p.product_name ,o.order_date ,o.order_reference
+        from customers c join products p on p.id=c.id
+        join orders o on p.id=o.customer_id
+        where c.name='Hope Crosby';
+10.select o.order_reference ,p.product_name ,pa.unit_price
+        from orders o join products p on o.id=p.id
+        join product_availability pa on pa.prod_id=p.id
+        join order_items oi on oi.order_id=o.id
+        where o.order_reference='ORD006';
+11.select p.product_name ,s.supplier_name,o.order_date,
+        o.order_reference ,c.name,oi.quantity
+        from products p join suppliers s on p.id =s.id
+        join orders o on o.id=s.id
+        join customers c on c.id=o.customer_id join
+        order_items oi on o.id=oi.order_id;
+12. select distinct s.country ,c.name
+        from orders o join order_items oi
+        on oi.order_id=o.id join suppliers s
+        on oi.supplier_id=s.id
+        join customers c on c.id=o.customer_id
+        where s.country='China';
+13.
+
+
 ```
 
 When you have finished all of the questions - open a pull request with your answers to the `Databases-Homework` repository.
@@ -41,10 +92,9 @@ Once you understand the database that you are going to work with, solve the foll
 5. Retrieve the 5 most expensive products
 6. Retrieve all the products with their corresponding suppliers. The result should only contain the columns `product_name`, `unit_price` and `supplier_name`
 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`.
-8. Retrieve all orders, including order items, from customer ID `1`. Include order id, reference, date and total cost (calculated as quantity * unit price).
+8. Retrieve all orders, including order items, from customer ID `1`. Include order id, reference, date and total cost (calculated as quantity \* unit price).
 9. Retrieve all orders, including order items, from customer named `Hope Crosby`
 10. Retrieve all the products in the order `ORD006`. The result should only contain the columns `product_name`, `unit_price` and `quantity`.
 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`.
 12. Retrieve the names of all customers who bought a product from a supplier based in China.
-13. List all orders giving customer name, order reference, order date and order total amount (quantity * unit price) in descending order of total.
-
+13. List all orders giving customer name, order reference, order date and order total amount (quantity \* unit price) in descending order of total.