Add challenges

src/data/courses/sql/chapters/sql-basics/lessons/challenge-1.md

@@ -3,42 +3,52 @@ title: Challenge 1
 description: Write a SQL query to find the total number of orders in the `orders` table.
 order: 300
 type: challenge
-defaultValue: |
-  SELECT
-    *
-  FROM
-    orders;
-
-  SELECT
-    COUNT(*)
-  FROM
-    orders;
 initSteps:
-  - CREATE TABLE orders (
+  - CREATE TABLE customers (
     id INTEGER PRIMARY KEY,
-    customer_id INTEGER,
-    order_date DATE,
-    total DECIMAL(10, 2)
+    name TEXT,
+    phone TEXT,
+    email TEXT
     );
-  - INSERT INTO orders (id, customer_id, order_date, total)
+  - INSERT INTO customers (id, name, phone, email)
     VALUES
-    (1, 1, '2021-01-01', 100.00),
-    (2, 2, '2021-01-02', 200.00),
-    (3, 1, '2021-01-03', 300.00),
-    (4, 3, '2021-01-04', 400.00),
-    (5, 2, '2021-01-05', 500.00);
+    (1, 'John', '555-123-4567', 'john@example.com'),
+    (2, 'Jane', '555-987-6543', 'jane@example.com'),
+    (3, 'Bob', NULL, 'bob@example.com'),
+    (4, 'David', NULL, 'david@example.com'),
+    (5, 'Charlie', '555-555-5555', 'charlie@example.com');
 expectedResults:
-  - columns: [total_orders]
+  - columns: [Full Name, Email]
     values:
-      - [5]
+      - ['John', 'john@example.com']
+      - ['Jane', 'jane@example.com']
+      - ['Bob', 'bob@example.com']
+      - ['David', 'david@example.com']
+      - ['Charlie', 'charlie@example.com']
 ---
 
-Write a SQL query to find the total number of orders in the `orders` table.
+Given the following customers `customers` table:
+
+| id  | name    | phone        | email               |
+| --- | ------- | ------------ | ------------------- |
+| 1   | John    | 555-123-4567 | john@example.com    |
+| 2   | Jane    | 555-987-6543 | jane@example.com    |
+| 3   | Bob     | NULL         | bob@example.com     |
+| 4   | David   | NULL         | david@example.com   |
+| 5   | Charlie | 555-555-5555 | charlie@example.com |
+
+Write a query to get the `name` and `email` of all customers.
 
 ## Result
 
-Your query should return a single column with the total number of orders in the `orders` table.
+Your output should look like this:
+
+| Full Name | Email               |
+| --------- | ------------------- |
+| John      | john@example.com    |
+| Jane      | jane@example.com    |
+| Bob       | bob@example.com     |
+| David     | david@example.com   |
+| Charlie   | charlie@example.com |
 
-- The column name should be `total_orders`.
-- The value should be the total number of orders in the `orders` table.
-- The query should return a single row with the total number of orders in the `orders` table.
+Notice that the `name` column is renamed to `Full Name` and the `email` column is renamed to `Email`.

src/data/courses/sql/chapters/sql-basics/lessons/challenge-2.md

@@ -0,0 +1,55 @@
+---
+title: Challenge 2
+description: Write a SQL query to find the total number of orders in the `orders` table.
+order: 300
+type: challenge
+initSteps:
+  - CREATE TABLE books (
+    id INTEGER PRIMARY KEY,
+    title TEXT,
+    price REAL,
+    discount REAL,
+    markup REAL
+    );
+  - INSERT INTO books (id, title, price, discount, markup)
+    VALUES
+    (1, 'The Great Gatsby', 10.99, 0.10, 1.10),
+    (2, 'To Kill a Mockingbird', 12.99, 0.15, 1.15),
+    (3, '1984', 8.99, 0.05, 1.05),
+    (4, 'The Catcher in the Rye', 11.99, 0.12, 1.12),
+    (5, 'The Hobbit', 9.99, 0.08, 1.15);
+expectedResults:
+  - columns: [title, final_price]
+    values:
+      - ['The Great Gatsby', 11.99]
+      - ['To Kill a Mockingbird', 13.99]
+      - ['1984', 9.99]
+      - ['The Catcher in the Rye', 12.99]
+      - ['The Hobbit', 11.06]
+---
+
+Given the following `books` table:
+
+| id  | title                  | price | discount | markup |
+| --- | ---------------------- | ----- | -------- | ------ |
+| 1   | The Great Gatsby       | 10.99 | 0.10     | 1.10   |
+| 2   | To Kill a Mockingbird  | 12.99 | 0.15     | 1.15   |
+| 3   | 1984                   | 8.99  | 0.05     | 1.05   |
+| 4   | The Catcher in the Rye | 11.99 | 0.12     | 1.12   |
+| 5   | The Hobbit             | 9.99  | 0.08     | 1.15   |
+
+Write an SQL query that returns the `title`, `final_price` of each book. The `final_price` is calculated using the following formula:
+
+```
+final_price = price + markup - discount
+```
+
+## Expected Results
+
+| title                  | final_price |
+| ---------------------- | ----------- |
+| The Great Gatsby       | 11.99       |
+| To Kill a Mockingbird  | 13.99       |
+| 1984                   | 9.99        |
+| The Catcher in the Rye | 12.99       |
+| The Hobbit             | 11.06       |

src/data/courses/sql/chapters/sql-basics/lessons/challenge-3.md

@@ -0,0 +1,54 @@
+---
+title: Challenge 3
+description: Write a SQL query to find the total number of orders in the `orders` table.
+order: 300
+type: challenge
+initSteps:
+  - CREATE TABLE orders (
+    id INTEGER PRIMARY KEY,
+    customer_id INTEGER,
+    total_price REAL,
+    status TEXT
+    );
+  - INSERT INTO orders (id, customer_id, total_price, status)
+    VALUES
+    (1, 1, 100.00, 'shipped'),
+    (2, 3, 150.00, 'pending'),
+    (3, 1, 200.00, 'shipped'),
+    (4, 3, 250.00, 'cancelled'),
+    (5, 2, 300.00, 'shipped'),
+    (6, 1, 300.00, 'pending'),
+    (7, 2, 300.00, 'shipped'),
+    (8, 3, 300.00, 'pending'),
+    (9, 1, 300.00, 'pending'),
+    (10, 2, 300.00, 'shipped');
+expectedResults:
+  - columns: [customer_id]
+    values:
+      - [3]
+      - [1]
+---
+
+Given the following `orders` table:
+
+| id  | customer_id | total_price | status    |
+| --- | ----------- | ----------- | --------- |
+| 1   | 1           | 100.00      | shipped   |
+| 2   | 3           | 150.00      | pending   |
+| 3   | 1           | 200.00      | shipped   |
+| 4   | 3           | 250.00      | cancelled |
+| 5   | 2           | 300.00      | shipped   |
+| 6   | 1           | 300.00      | pending   |
+| 7   | 2           | 300.00      | shipped   |
+| 8   | 3           | 300.00      | pending   |
+| 9   | 1           | 300.00      | pending   |
+| 10  | 2           | 300.00      | shipped   |
+
+Write an SQL query to get a unique list of `customer_id` values where the status is `pending`.
+
+## Expected Results
+
+| customer_id |
+| ----------- |
+| 1           |
+| 3           |

src/data/courses/sql/chapters/sql-basics/lessons/comments.md

@@ -17,13 +17,13 @@ Single line comments are created using `--` followed by the comment text. For ex
 -- They are ignored by the database.
 SELECT * FROM customers;
 
--- You can use them to comment 
+-- You can use them to comment
 -- out parts of your query.
 SELECT * FROM customers; -- WHERE id = 1;
 
 -- Add notes to your query for later reference.
-SELECT * 
-FROM customers 
+SELECT *
+FROM customers
 WHERE country = 'USA';  -- USA users only
 ```
 
@@ -39,18 +39,16 @@ Multi line comments are created using `/*` followed by the comment text and `*/`
 SELECT * FROM customers;
 
 /*
-    -- Other queries for our database
-    SELECT * FROM customers;
-    SELECT * FROM orders;
-    SELECT * FROM books;
+SELECT * FROM customers;
+SELECT * FROM orders;
+SELECT * FROM books;
 */
+```
+
+You can also use them to comment out parts of your query. e.g. here we are commenting out the country condition so we are only getting orders that are shipped.
 
--- You can also use them to comment 
--- out parts of your query. e.g. 
--- here we are commenting out the
--- country condition so we are only 
--- getting orders that are shipped.
-SELECT * 
-FROM orders 
+```sql
+SELECT *
+FROM orders
 WHERE /* country = 'USA' AND */ status = 'shipped';
-```
+```