1.1_sql_project.sql

/* Welcome to the SQL mini project. For this project, you will use
Springboard' online SQL platform, which you can log into through the
following link:

https://sql.springboard.com/
Username: student
Password: learn_sql@springboard

The data you need is in the "country_club" database. This database
contains 3 tables:
    i) the "Bookings" table,
    ii) the "Facilities" table, and
    iii) the "Members" table.

Note that, if you need to, you can also download these tables locally.

In the mini project, you'll be asked a series of questions. You can
solve them using the platform, but for the final deliverable,
paste the code for each solution into this script, and upload it
to your GitHub.

Before starting with the questions, feel free to take your time,
exploring the data, and getting acquainted with the 3 tables. */



/* Q1: Some of the facilities charge a fee to members, but some do not.
Please list the names of the facilities that do. */
SELECT name, membercost
	FROM Facilities
WHERE membercost > 0

/* Q2: How many facilities do not charge a fee to members? */
SELECT	COUNT(membercost = 0) AS free_facilities
	FROM Facilities

/* Q3: How can you produce a list of facilities that charge a fee to members,
where the fee is less than 20% of the facility's monthly maintenance cost?
Return the facid, facility name, member cost, and monthly maintenance of the
facilities in question. */
SELECT	facid,
		name,
		membercost,
		monthlymaintenance
	FROM Facilities
WHERE membercost > 0 AND membercost < (0.2 * monthlymaintenance)

/* Q4: How can you retrieve the details of facilities with ID 1 and 5?
Write the query without using the OR operator. */
SELECT *
FROM Facilities
WHERE facid IN (1, 5)

/* Q5: How can you produce a list of facilities, with each labelled as
'cheap' or 'expensive', depending on if their monthly maintenance cost is
more than $100? Return the name and monthly maintenance of the facilities
in question. */
SELECT	name, 
		monthlymaintenance,
		CASE WHEN monthlymaintenance <= 100 THEN 'cheap'
			ELSE 'expensive' END AS price_status
FROM Facilities

/* Q6: You'd like to get the first and last name of the last member(s)
who signed up. Do not use the LIMIT clause for your solution. */

SELECT	firstname,
		surname,
		joindate
FROM Members
WHERE joindate = (SELECT MAX(joindate) FROM Members)

/* Q7: How can you produce a list of all members who have used a tennis court?
Include in your output the name of the court, and the name of the member
formatted as a single column. Ensure no duplicate data, and order by
the member name. */

SELECT	DISTINCT Facilities.name AS court_name,
		concat(Members.firstname, ' ', Members.surname) AS member_name
FROM Bookings
JOIN Members ON Bookings.memid = Members.memid
JOIN Facilities ON Bookings.facid = Facilities.facid AND Facilities.facid IN (0,1)
ORDER BY 2


/* Q8: How can you produce a list of bookings on the day of 2012-09-14 which
will cost the member (or guest) more than $30? Remember that guests have
different costs to members (the listed costs are per half-hour 'slot'), and
the guest user's ID is always 0. Include in your output the name of the
facility, the name of the member formatted as a single column, and the cost.
Order by descending cost, and do not use any subqueries. */

SELECT	Facilities.name AS facility_name,
	CASE WHEN Members.memid = 0 THEN 'guest'
		ELSE concat(Members.firstname, ' ', Members.surname) END AS guest_member_name,
	CASE WHEN Bookings.memid = 0 THEN Facilities.guestcost * Bookings.slots
		ELSE Facilities.membercost * Bookings.slots END AS cost
FROM Bookings
	JOIN Members ON Bookings.memid = Members.memid
	JOIN Facilities ON Bookings.facid = Facilities.facid
WHERE CAST(Bookings.starttime AS date) =  '2012-09-14'
HAVING cost > 30
ORDER BY cost DESC

/* Q9: This time, produce the same result as in Q8, but using a subquery. */

SELECT 
tt.fac_name as facility_name, 
tt.guest_member_name as member_name,
tt.cost
FROM(
    SELECT Facilities.name AS fac_name,
    CASE WHEN Members.memid = 0 THEN 'guest'
    ELSE concat(Members.firstname, ' ', Members.surname) END AS guest_member_name,
    CASE WHEN Bookings.memid = 0 THEN Facilities.guestcost * Bookings.slots
    ELSE Facilities.membercost * Bookings.slots END AS cost,
    Bookings.starttime as start_time
    FROM Bookings
    JOIN Members ON Bookings.memid = Members.memid
    JOIN Facilities ON Bookings.facid = Facilities.facid
) as tt
WHERE CAST(tt.start_time AS date) = '2012-09-14'
HAVING tt.cost > 30
ORDER BY tt.cost DESC

/* Q10: Produce a list of facilities with a total revenue less than 1000.
The output of facility name and total revenue, sorted by revenue. Remember
that there's a different cost for guests and members! */
    
SELECT	Facilities.name AS facility_name,
SUM(CASE WHEN Bookings.memid = 0 THEN Facilities.guestcost * Bookings.slots
	ELSE Facilities.membercost * Bookings.slots END) as total_rev
FROM Facilities
LEFT OUTER JOIN Bookings
ON Facilities.facid = Bookings.facid
GROUP BY facility_name
HAVING  total_rev < 1000