Clean up QUERY.md by removing sample data

QUERY.md

@@ -1,74 +1,46 @@
-# Sample SQL Queries - Expected Output
-
-This document provides sample data and the expected outputs for the SQL queries defined in the assignment.
-
-## Sample Data (Input)
-
-### Users Table
-| user_id | name | email | phone | role |
-| :--- | :--- | :--- | :--- | :--- |
-| 1 | Alice | alice@example.com | 1234567890 | Customer |
-| 2 | Bob | bob@example.com | 0987654321 | Admin |
-| 3 | Charlie | charlie@example.com | 1122334455 | Customer |
-
-### Vehicles Table
-| vehicle_id | name | type | model | registration_number | rental_price | status |
-| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
-| 1 | Toyota Corolla | car | 2022 | ABC-123 | 50 | available |
-| 2 | Honda Civic | car | 2021 | DEF-456 | 60 | rented |
-| 3 | Yamaha R15 | bike | 2023 | GHI-789 | 30 | available |
-| 4 | Ford F-150 | truck | 2020 | JKL-012 | 100 | maintenance |
-
-### Bookings Table
-| booking_id | user_id | vehicle_id | start_date | end_date | status | total_cost |
-| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
-| 1 | 1 | 2 | 2023-10-01 | 2023-10-05 | completed | 240 |
-| 2 | 1 | 2 | 2023-11-01 | 2023-11-03 | completed | 120 |
-| 3 | 3 | 2 | 2023-12-01 | 2023-12-02 | confirmed | 60 |
-| 4 | 1 | 1 | 2023-12-10 | 2023-12-12 | pending | 100 |
-
----
-
-## Expected Query Results
-
-### Query 1: JOIN
-**Requirement**: Retrieve booking information along with Customer name and Vehicle name.
-
-**Expected Output**:
-| booking_id | customer_name | vehicle_name | start_date | end_date | status |
-| :--- | :--- | :--- | :--- | :--- | :--- |
-| 1 | Alice | Honda Civic | 2023-10-01 | 2023-10-05 | completed |
-| 2 | Alice | Honda Civic | 2023-11-01 | 2023-11-03 | completed |
-| 3 | Charlie | Honda Civic | 2023-12-01 | 2023-12-02 | confirmed |
-| 4 | Alice | Toyota Corolla | 2023-12-10 | 2023-12-12 | pending |
-
----
-
-### Query 2: EXISTS
-**Requirement**: Find all vehicles that have never been booked.
-
-**Expected Output**:
-| vehicle_id | name | type | model | registration_number | rental_price | status |
-| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
-| 3 | Yamaha R15 | bike | 2023 | GHI-789 | 30 | available |
-| 4 | Ford F-150 | truck | 2020 | JKL-012 | 100 | maintenance |
-
----
-
-### Query 3: WHERE
-**Requirement**: Retrieve all available vehicles of a specific type (e.g. cars).
-
-**Expected Output**:
-| vehicle_id | name | type | model | registration_number | rental_price | status |
-| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
-| 1 | Toyota Corolla | car | 2022 | ABC-123 | 50 | available |
-
----
-
-### Query 4: GROUP BY and HAVING
-**Requirement**: Find the total number of bookings for each vehicle and display only those vehicles that have more than 2 bookings.
-
-**Expected Output**:
-| vehicle_name | total_bookings |
-| :--- | :--- |
-| Honda Civic | 3 |
+SELECT
+    b.id AS booking_id,
+    u.name AS customer_name,
+    v.vehicle_name,
+    b.start_date,
+    b.end_date,
+    b.status
+FROM bookings b
+INNER JOIN "user" u ON b.user_id = u.id
+INNER JOIN vehicle v ON b.vehicle_id = v.id
+ORDER BY b.id;
+
+SELECT
+    v.id AS vehicle_id,
+    v.vehicle_name,
+    v.type,
+    v.model,
+    v.reg_number,
+    v.rental_price,
+    v.availability_status
+FROM vehicle v
+WHERE NOT EXISTS (
+    SELECT 1
+    FROM bookings b
+    WHERE b.vehicle_id = v.id
+);
+
+SELECT
+    v.id AS vehicle_id,
+    v.vehicle_name,
+    v.type,
+    v.model,
+    v.reg_number,
+    v.rental_price,
+    v.availability_status
+FROM vehicle v
+WHERE v.availability_status = 'available'
+  AND v.type = 'car';
+
+SELECT
+    v.vehicle_name,
+    COUNT(b.id) AS total_bookings
+FROM bookings b
+INNER JOIN vehicle v ON b.vehicle_id = v.id
+GROUP BY v.vehicle_name
+HAVING COUNT(b.id) > 2;