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Original file line number Diff line number Diff line change
@@ -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.
Original file line number Diff line number Diff line change
@@ -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;
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
package g3501_3600.s3564_seasonal_sales_analysis

import org.hamcrest.CoreMatchers
import org.hamcrest.MatcherAssert
import org.hamcrest.CoreMatchers.equalTo
import org.hamcrest.MatcherAssert.assertThat
import org.junit.jupiter.api.Test
import org.zapodot.junit.db.annotations.EmbeddedDatabase
import org.zapodot.junit.db.annotations.EmbeddedDatabaseTest
Expand Down Expand Up @@ -66,27 +66,27 @@ internal class MysqlTest {
.collect(Collectors.joining("\n"))
.replace("#.*?\\r?\\n".toRegex(), ""),
).use { resultSet ->
MatcherAssert.assertThat<Boolean>(resultSet.next(), CoreMatchers.equalTo<Boolean>(true))
MatcherAssert.assertThat<String>(resultSet.getNString(1), CoreMatchers.equalTo<String>("Fall"))
MatcherAssert.assertThat<String>(resultSet.getNString(2), CoreMatchers.equalTo<String>("Apparel"))
MatcherAssert.assertThat<String>(resultSet.getNString(3), CoreMatchers.equalTo<String>("10"))
MatcherAssert.assertThat<String>(resultSet.getNString(4), CoreMatchers.equalTo<String>("120"))
MatcherAssert.assertThat<Boolean>(resultSet.next(), CoreMatchers.equalTo<Boolean>(true))
MatcherAssert.assertThat<String>(resultSet.getNString(1), CoreMatchers.equalTo<String>("Spring"))
MatcherAssert.assertThat<String>(resultSet.getNString(2), CoreMatchers.equalTo<String>("Kitchen"))
MatcherAssert.assertThat<String>(resultSet.getNString(3), CoreMatchers.equalTo<String>("3"))
MatcherAssert.assertThat<String>(resultSet.getNString(4), CoreMatchers.equalTo<String>("54"))
MatcherAssert.assertThat<Boolean>(resultSet.next(), CoreMatchers.equalTo<Boolean>(true))
MatcherAssert.assertThat<String>(resultSet.getNString(1), CoreMatchers.equalTo<String>("Summer"))
MatcherAssert.assertThat<String>(resultSet.getNString(2), CoreMatchers.equalTo<String>("Tech"))
MatcherAssert.assertThat<String>(resultSet.getNString(3), CoreMatchers.equalTo<String>("5"))
MatcherAssert.assertThat<String>(resultSet.getNString(4), CoreMatchers.equalTo<String>("100"))
MatcherAssert.assertThat<Boolean>(resultSet.next(), CoreMatchers.equalTo<Boolean>(true))
MatcherAssert.assertThat<String>(resultSet.getNString(1), CoreMatchers.equalTo<String>("Winter"))
MatcherAssert.assertThat<String>(resultSet.getNString(2), CoreMatchers.equalTo<String>("Apparel"))
MatcherAssert.assertThat<String>(resultSet.getNString(3), CoreMatchers.equalTo<String>("9"))
MatcherAssert.assertThat<String>(resultSet.getNString(4), CoreMatchers.equalTo<String>("110"))
MatcherAssert.assertThat<Boolean>(resultSet.next(), CoreMatchers.equalTo<Boolean>(false))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(true))
assertThat<String>(resultSet.getNString(1), equalTo<String>("Fall"))
assertThat<String>(resultSet.getNString(2), equalTo<String>("Apparel"))
assertThat<String>(resultSet.getNString(3), equalTo<String>("10"))
assertThat<String>(resultSet.getNString(4), equalTo<String>("120"))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(true))
assertThat<String>(resultSet.getNString(1), equalTo<String>("Spring"))
assertThat<String>(resultSet.getNString(2), equalTo<String>("Kitchen"))
assertThat<String>(resultSet.getNString(3), equalTo<String>("3"))
assertThat<String>(resultSet.getNString(4), equalTo<String>("54"))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(true))
assertThat<String>(resultSet.getNString(1), equalTo<String>("Summer"))
assertThat<String>(resultSet.getNString(2), equalTo<String>("Tech"))
assertThat<String>(resultSet.getNString(3), equalTo<String>("5"))
assertThat<String>(resultSet.getNString(4), equalTo<String>("100"))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(true))
assertThat<String>(resultSet.getNString(1), equalTo<String>("Winter"))
assertThat<String>(resultSet.getNString(2), equalTo<String>("Apparel"))
assertThat<String>(resultSet.getNString(3), equalTo<String>("9"))
assertThat<String>(resultSet.getNString(4), equalTo<String>("110"))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(false))
}
}
}
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,99 @@
package g3501_3600.s3570_find_books_with_no_available_copies

import org.hamcrest.CoreMatchers.equalTo
import org.hamcrest.MatcherAssert.assertThat
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
import java.io.BufferedReader
import java.io.FileNotFoundException
import java.io.FileReader
import java.sql.SQLException
import java.util.stream.Collectors
import javax.sql.DataSource

@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);"
),
],
)
internal class MysqlTest {
@Test
@Throws(SQLException::class, FileNotFoundException::class)
fun testScript(@EmbeddedDatabase dataSource: DataSource) {
dataSource.connection.use { connection ->
connection.createStatement().use { statement ->
statement.executeQuery(
BufferedReader(
FileReader(
(
"src/main/kotlin/g3501_3600/" +
"s3570_find_books_with_no_available_copies/" +
"script.sql"
),
),
)
.lines()
.collect(Collectors.joining("\n"))
.replace("#.*?\\r?\\n".toRegex(), ""),
).use { resultSet ->
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(true))
assertThat<String>(resultSet.getNString(1), equalTo<String>("1"))
assertThat<String>(
resultSet.getNString(2),
equalTo<String>("The Great Gatsby"),
)
assertThat<String>(
resultSet.getNString(3),
equalTo<String>("F. Scott"),
)
assertThat<String>(resultSet.getNString(4), equalTo<String>("Fiction"))
assertThat<String>(resultSet.getNString(5), equalTo<String>("1925"))
assertThat<String>(resultSet.getNString(6), equalTo<String>("3"))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(true))
assertThat<String>(resultSet.getNString(1), equalTo<String>("3"))
assertThat<String>(resultSet.getNString(2), equalTo<String>("1984"))
assertThat<String>(
resultSet.getNString(3),
equalTo<String>("George Orwell"),
)
assertThat<String>(
resultSet.getNString(4),
equalTo<String>("Dystopian"),
)
assertThat<String>(resultSet.getNString(5), equalTo<String>("1949"))
assertThat<String>(resultSet.getNString(6), equalTo<String>("1"))
assertThat<Boolean>(resultSet.next(), equalTo<Boolean>(false))
}
}
}
}
}