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src/data/courses/sql/chapters/sql-basics/lessons/challenge-4.md

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+---
+title: Challenge 4
+description: Write a SQL query to find the total number of orders in the `orders` table.
+order: 400
+type: challenge
+initSteps:
+  - CREATE TABLE books (
+    id INTEGER PRIMARY KEY,
+    title TEXT,
+    genre TEXT,
+    price REAL,
+    stock INTEGER,
+    year INTEGER
+    );
+  - INSERT INTO books (id, title, genre, price, stock, year)
+    VALUES
+    (1, 'The Great Adventure', 'Fiction', 15.99, 12, 2020),
+    (2, 'Mystery of the Night', 'Mystery', 12.50, 5, 2018),
+    (3, 'Science Explained', 'Science', 20.00, 0, 2019),
+    (4, 'Cooking Made Easy', 'Cooking', 18.99, 8, 2021),
+    (5, 'History Revisited', 'History', 10.99, 20, 2017),
+    (6, 'Fictional Reality', 'Fiction', 25.99, 3, 2022);
+expectedResults:
+  - columns: [id, title, genre, price, stock, year]
+    values:
+      - [1, 'The Great Adventure', 'Fiction', 15.99, 12, 2020]
+---
+
+Given the following `books` table:
+
+| id  | title                | genre   | price | stock | year |
+| --- | -------------------- | ------- | ----- | ----- | ---- |
+| 1   | The Great Adventure  | Fiction | 15.99 | 12    | 2020 |
+| 2   | Mystery of the Night | Mystery | 12.50 | 5     | 2018 |
+| 3   | Science Explained    | Science | 20.00 | 0     | 2019 |
+| 4   | Cooking Made Easy    | Cooking | 18.99 | 8     | 2021 |
+| 5   | History Revisited    | History | 10.99 | 20    | 2017 |
+| 6   | Fictional Reality    | Fiction | 25.99 | 3     | 2022 |
+
+Write a query to find books that match the following conditions:
+
+- The book is either **Fiction** or **Mystery**.
+- It costs **less than $20**.
+- It was **published after 2018** OR has **more than 10 copies in stock**.
+
+## Expected Results
+
+| id  | title               | genre   | price | stock | year |
+| --- | ------------------- | ------- | ----- | ----- | ---- |
+| 1   | The Great Adventure | Fiction | 15.99 | 12    | 2020 |