From 54a32898c135ecc26fdbbfcebba2bb2b4af44bd7 Mon Sep 17 00:00:00 2001 From: Valentyn Kolesnikov Date: Wed, 4 Jun 2025 06:17:21 +0300 Subject: [PATCH] Added task 3570 --- .../readme.md | 106 ++++++++++++++++++ .../script.sql | 38 +++++++ .../MysqlTest.java | 82 ++++++++++++++ 3 files changed, 226 insertions(+) create mode 100644 src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/readme.md create mode 100644 src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/script.sql create mode 100644 src/test/java/g3501_3600/s3570_find_books_with_no_available_copies/MysqlTest.java diff --git a/src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/readme.md b/src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/readme.md new file mode 100644 index 000000000..bcbc98bf6 --- /dev/null +++ b/src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/readme.md @@ -0,0 +1,106 @@ +3570\. Find Books with No Available Copies + +Easy + +Table: `library_books` + + +------------------+---------+ + | Column Name | Type | + +------------------+---------+ + | book_id | int | + | title | varchar | + | author | varchar | + | genre | varchar | + | publication_year | int | + | total_copies | int | + +------------------+---------+ + book_id is the unique identifier for this table. + Each row contains information about a book in the library, including the total number of copies owned by the library. + +Table: `borrowing_records` + + +---------------+---------+ + | Column Name | Type | + |----------------|---------| + | record_id | int | + | book_id | int | + | borrower_name | varchar | + | borrow_date | date | + | return_date | date | + +----------------+---------+ + record_id is the unique identifier for this table. + Each row represents a borrowing transaction and return_date is NULL if the book is currently borrowed and hasn't been returned yet. + +Write a solution to find **all books** that are **currently borrowed (not returned)** and have **zero copies available** in the library. + +* A book is considered **currently borrowed** if there exists a borrowing record with a **NULL** `return_date` + +Return _the result table ordered by current borrowers in **descending** order, then by book title in **ascending** order._ + +The result format is in the following example. + +**Example:** + +**Input:** + +library\_books table: + + +---------+--------------------------+----------------+-----------+------------------+--------------+ + | book_id | Title | Author | Genre | Publication Year | Total Copies | + |---------|--------------------------|----------------|-----------|------------------|--------------| + | 1 | The Great Gatsby | F. Scott | Fiction | 1925 | 3 | + | 2 | To Kill a Mockingbird | Harper Lee | Fiction | 1960 | 3 | + | 3 | 1984 | George Orwell | Dystopian | 1949 | 1 | + | 4 | Pride and Prejudice | Jane Austen | Romance | 1813 | 2 | + | 5 | The Catcher in the Rye | J.D. Salinger | Fiction | 1951 | 1 | + | 6 | Brave New World | Aldous Huxley | Dystopian | 1932 | 4 | + +---------+--------------------------+----------------+-----------+------------------+--------------+ + +borrowing\_records table: + + +-----------+---------+---------------+-------------+-------------+ + | record_id | book_id | borrower_name | borrow_date | return_date | + |-----------|---------|---------------|-------------|-------------| + | 1 | 1 | Alice Smith | 2024-01-15 | NULL | + | 2 | 1 | Bob Johnson | 2024-01-20 | NULL | + | 3 | 2 | Carol White | 2024-01-10 | 2024-01-25 | + | 4 | 3 | David Brown | 2024-02-01 | NULL | + | 5 | 4 | Emma Wilson | 2024-01-05 | NULL | + | 6 | 5 | Frank Davis | 2024-01-18 | 2024-02-10 | + | 7 | 1 | Grace Miller | 2024-02-05 | NULL | + | 8 | 6 | Henry Taylor | 2024-01-12 | NULL | + | 9 | 2 | Ivan Clark | 2024-02-12 | NULL | + | 10 | 2 | Jane Adams | 2024-02-15 | NULL | + +-----------+---------+---------------+-------------+-------------+ + +**Output:** + + +---------+-------------------+----------------+-----------+------------------+-------------------+ + | book_id | Title | Author | Genre | Publication Year | Current Borrowers | + |---------|-------------------|----------------|-----------|------------------|-------------------| + | 1 | The Great Gatsby | F. Scott | Fiction | 1925 | 3 | + | 3 | 1984 | George Orwell | Dystopian | 1949 | 1 | + +---------+-------------------+----------------+-----------+------------------+-------------------+ + +**Explanation:** + +* **The Great Gatsby (book\_id = 1):** + * Total copies: 3 + * Currently borrowed by Alice Smith, Bob Johnson, and Grace Miller (3 borrowers) + * Available copies: 3 - 3 = 0 + * Included because available\_copies = 0 +* **1984 (book\_id = 3):** + * Total copies: 1 + * Currently borrowed by David Brown (1 borrower) + * Available copies: 1 - 1 = 0 + * Included because available\_copies = 0 +* **Books not included:** + * To Kill a Mockingbird (book\_id = 2): Total copies = 3, current borrowers = 2, available = 1 + * Pride and Prejudice (book\_id = 4): Total copies = 2, current borrowers = 1, available = 1 + * The Catcher in the Rye (book\_id = 5): Total copies = 1, current borrowers = 0, available = 1 + * Brave New World (book\_id = 6): Total copies = 4, current borrowers = 1, available = 3 +* **Result ordering:** + * The Great Gatsby appears first with 3 current borrowers + * 1984 appears second with 1 current borrower + +Output table is ordered by current\_borrowers in descending order, then by book\_title in ascending order. \ No newline at end of file diff --git a/src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/script.sql b/src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/script.sql new file mode 100644 index 000000000..db34b0ea7 --- /dev/null +++ b/src/main/java/g3501_3600/s3570_find_books_with_no_available_copies/script.sql @@ -0,0 +1,38 @@ +# Write your MySQL query statement below +# #Easy #Database #2025_06_03_Time_512_ms_(100.00%)_Space_0.0_MB_(100.00%) +SELECT + book_id, + MAX(title) AS title, + MAX(author) AS author, + MAX(genre) AS genre, + MAX(publication_year) AS publication_year, + MAX(total_copies) AS current_borrowers +FROM ( + SELECT + book_id, + title, + author, + genre, + publication_year, + total_copies, + total_copies AS total_remain + FROM library_books + UNION ALL + SELECT + book_id, + '' AS title, + '' AS author, + '' AS genre, + 1000 AS publication_year, + 0 AS total_copies, + -1 AS total_remain + FROM borrowing_records + WHERE return_date IS NULL +) AS sub +GROUP BY + book_id +HAVING + SUM(total_remain) = 0 +ORDER BY + current_borrowers DESC, + title ASC; diff --git a/src/test/java/g3501_3600/s3570_find_books_with_no_available_copies/MysqlTest.java b/src/test/java/g3501_3600/s3570_find_books_with_no_available_copies/MysqlTest.java new file mode 100644 index 000000000..4ae19d88e --- /dev/null +++ b/src/test/java/g3501_3600/s3570_find_books_with_no_available_copies/MysqlTest.java @@ -0,0 +1,82 @@ +package g3501_3600.s3570_find_books_with_no_available_copies; + +import static org.hamcrest.CoreMatchers.equalTo; +import static org.hamcrest.MatcherAssert.assertThat; + +import java.io.BufferedReader; +import java.io.FileNotFoundException; +import java.io.FileReader; +import java.sql.Connection; +import java.sql.ResultSet; +import java.sql.SQLException; +import java.sql.Statement; +import java.util.stream.Collectors; +import javax.sql.DataSource; +import org.junit.jupiter.api.Test; +import org.zapodot.junit.db.annotations.EmbeddedDatabase; +import org.zapodot.junit.db.annotations.EmbeddedDatabaseTest; +import org.zapodot.junit.db.common.CompatibilityMode; + +@EmbeddedDatabaseTest( + compatibilityMode = CompatibilityMode.MySQL, + initialSqls = + "CREATE TABLE library_books(book_id INTEGER, title VARCHAR(255)" + + ", author VARCHAR(255), genre VARCHAR(255), publication_year " + + "INTEGER, total_copies INTEGER); " + + "INSERT INTO library_books (book_id, title, author, genre, " + + "publication_year, total_copies) VALUES " + + "(1, 'The Great Gatsby', 'F. Scott', 'Fiction', 1925, 3)," + + "(2, 'To Kill a Mockingbird', 'Harper Lee', 'Fiction', 1960, 3)," + + "(3, '1984', 'George Orwell', 'Dystopian', 1949, 1)," + + "(4, 'Pride and Prejudice', 'Jane Austen', 'Romance', 1813, 2)," + + "(5, 'The Catcher in the Rye','J.D. Salinger', 'Fiction', 1951, 1)," + + "(6, 'Brave New World', 'Aldous Huxley', 'Dystopian', 1932, 4);" + + "CREATE TABLE borrowing_records(record_id INTEGER, book_id INTEGER" + + ", borrower_name VARCHAR(255), borrow_date DATE, return_date DATE); " + + "INSERT INTO borrowing_records(record_id, book_id, borrower_name, " + + "borrow_date, return_date) VALUES " + + "(1, 1, 'Alice Smith', '2024-01-15', NULL)," + + "(2, 1, 'Bob Johnson', '2024-01-20', NULL)," + + "(3, 2, 'Carol White', '2024-01-10', '2024-01-25')," + + "(4, 3, 'David Brown', '2024-02-01', NULL)," + + "(5, 4, 'Emma Wilson', '2024-01-05', NULL)," + + "(6, 5, 'Frank Davis', '2024-01-18', '2024-02-10')," + + "(7, 1, 'Grace Miller', '2024-02-05', NULL)," + + "(8, 6, 'Henry Taylor', '2024-01-12', NULL)," + + "(9, 2, 'Ivan Clark', '2024-02-12', NULL)," + + "(10,2, 'Jane Adams', '2024-02-15', NULL);") +class MysqlTest { + @Test + void testScript(@EmbeddedDatabase DataSource dataSource) + throws SQLException, FileNotFoundException { + try (final Connection connection = dataSource.getConnection()) { + try (final Statement statement = connection.createStatement(); + final ResultSet resultSet = + statement.executeQuery( + new BufferedReader( + new FileReader( + "src/main/java/g3501_3600/" + + "s3570_find_books_with_no_available_copies/" + + "script.sql")) + .lines() + .collect(Collectors.joining("\n")) + .replaceAll("#.*?\\r?\\n", ""))) { + assertThat(resultSet.next(), equalTo(true)); + assertThat(resultSet.getNString(1), equalTo("1")); + assertThat(resultSet.getNString(2), equalTo("The Great Gatsby")); + assertThat(resultSet.getNString(3), equalTo("F. Scott")); + assertThat(resultSet.getNString(4), equalTo("Fiction")); + assertThat(resultSet.getNString(5), equalTo("1925")); + assertThat(resultSet.getNString(6), equalTo("3")); + assertThat(resultSet.next(), equalTo(true)); + assertThat(resultSet.getNString(1), equalTo("3")); + assertThat(resultSet.getNString(2), equalTo("1984")); + assertThat(resultSet.getNString(3), equalTo("George Orwell")); + assertThat(resultSet.getNString(4), equalTo("Dystopian")); + assertThat(resultSet.getNString(5), equalTo("1949")); + assertThat(resultSet.getNString(6), equalTo("1")); + assertThat(resultSet.next(), equalTo(false)); + } + } + } +}