Added tasks 602, 610, 619, 1045

Author: javadev

README.md

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+602\. Friend Requests II: Who Has the Most Friends
+
+Medium
+
+SQL Schema
+
+Table: `RequestAccepted`
+
+    +----------------+---------+ 
+    | Column Name    | Type    | 
+    +----------------+---------+ 
+    | requester_id   | int     | 
+    | accepter_id    | int     | 
+    | accept_date    | date    | 
+    +----------------+---------+ 
+    
+(requester_id, accepter_id) is the primary key for this table. This table contains the ID of the user who sent the request, the ID of the user who received the request, and the date when the request was accepted.
+
+Write an SQL query to find the people who have the most friends and the most friends number.
+
+The test cases are generated so that only one person has the most friends.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:** RequestAccepted table: 
+
+    +--------------+-------------+-------------+ 
+    | requester_id | accepter_id | accept_date | 
+    +--------------+-------------+-------------+ 
+    | 1            | 2           | 2016/06/03  | 
+    | 1            | 3           | 2016/06/08  | 
+    | 2            | 3           | 2016/06/08  | 
+    | 3            | 4           | 2016/06/09  | 
+    +--------------+-------------+-------------+
+
+**Output:** 
+
+    +----+-----+ 
+    | id | num | 
+    +----+-----+ 
+    | 3  | 3   | 
+    +----+-----+
+
+**Explanation:** The person with id 3 is a friend of people 1, 2, and 4, so he has three friends in total, which is the most number than any others.
+
+**Follow up:** In the real world, multiple people could have the same most number of friends. Could you find all these people in this case?

src/main/java/g0601_0700/s0602_friend_requests_ii_who_has_the_most_friends/readme.md

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+# Write your MySQL query statement below
+# #Medium #Database #2023_06_05_Time_510_ms_(60.15%)_Space_0B_(100.00%)
+SELECT req AS id, COUNT(acc) AS num
+FROM
+((SELECT requester_id AS req, accepter_id AS acc
+FROM requestaccepted)
+UNION
+(SELECT accepter_id AS req, requester_id AS acc
+FROM requestaccepted)) t
+GROUP BY req
+ORDER BY num DESC
+LIMIT 1

src/main/java/g0601_0700/s0602_friend_requests_ii_who_has_the_most_friends/script.sql

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+610\. Triangle Judgement
+
+Easy
+
+SQL Schema
+
+Table: `Triangle`
+
+    +-------------+------+ 
+    | Column Name | Type | 
+    +-------------+------+ 
+    | x           | int  | 
+    | y           | int  | 
+    | z           | int  | 
+    +-------------+------+ 
+
+(x, y, z) is the primary key column for this table. 
+
+Each row of this table contains the lengths of three line segments.
+
+Write an SQL query to report for every three line segments whether they can form a triangle.
+
+Return the result table in **any order**.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:** Triangle table:
+    
+    +----+----+----+ 
+    | x  | y  | z  | 
+    +----+----+----+ 
+    | 13 | 15 | 30 | 
+    | 10 | 20 | 15 | 
+    +----+----+----+
+
+**Output:** 
+    
+    +----+----+----+----------+ 
+    | x  | y  | z  | triangle | 
+    +----+----+----+----------+ 
+    | 13 | 15 | 30 | No       | 
+    | 10 | 20 | 15 | Yes      |
+    +----+----+----+----------+ 

src/main/java/g0601_0700/s0610_triangle_judgement/readme.md

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+# Write your MySQL query statement below
+# #Easy #Database #2023_06_05_Time_499_ms_(62.77%)_Space_0B_(100.00%)
+SELECT *,
+    CASE WHEN x+y>z AND y+z>x AND z+x>y THEN 'Yes' ELSE 'No' END AS triangle
+FROM Triangle

src/main/java/g0601_0700/s0610_triangle_judgement/script.sql

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+619\. Biggest Single Number
+
+Easy
+
+SQL Schema
+
+Table: `MyNumbers`
+
+    +-------------+------+ 
+    | Column Name | Type | 
+    +-------------+------+ 
+    | num         | int  |
+    +-------------+------+ 
+
+There is no primary key for this table. It may contain duplicates.
+
+Each row of this table contains an integer.
+
+A **single number** is a number that appeared only once in the `MyNumbers` table.
+
+Write an SQL query to report the largest **single number**. If there is no **single number**, report `null`.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:** MyNumbers table: 
+
+    +-----+ 
+    | num | 
+    +-----+ 
+    | 8   | 
+    | 8   | 
+    | 3   | 
+    | 3   | 
+    | 1   | 
+    | 4   | 
+    | 5   | 
+    | 6   | 
+    +-----+
+
+**Output:** 
+
+    +-----+ 
+    | num | 
+    +-----+ 
+    | 6   | 
+    +-----+
+
+**Explanation:** The single numbers are 1, 4, 5, and 6. Since 6 is the largest single number, we return it.
+
+**Example 2:**
+
+**Input:** MyNumbers table: 
+
+    +-----+ 
+    | num | 
+    +-----+ 
+    | 8   | 
+    | 8   | 
+    | 7   | 
+    | 7   | 
+    | 3   | 
+    | 3   | 
+    | 3   | 
+    +-----+
+
+**Output:** 
+
+    +------+ 
+    | num  | 
+    +------+ 
+    | null | 
+    +------+
+
+**Explanation:** There are no single numbers in the input table so we return null. 

src/main/java/g0601_0700/s0619_biggest_single_number/readme.md

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+# Write your MySQL query statement below
+# #Easy #Database #2023_06_05_Time_779_ms_(66.08%)_Space_0B_(100.00%)
+SELECT MAX(num) AS num
+FROM (SELECT num, COUNT(num)
+      FROM MyNumbers
+      GROUP BY num
+      HAVING COUNT(num) = 1) t

src/main/java/g0601_0700/s0619_biggest_single_number/script.sql

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+1045\. Customers Who Bought All Products
+
+Medium
+
+SQL Schema
+
+Table: `Customer`
+
+    +-------------+---------+ 
+    | Column Name | Type    | 
+    +-------------+---------+ 
+    | customer_id | int     | 
+    | product_key | int     | 
+    +-------------+---------+ 
+
+There is no primary key for this table. It may contain duplicates. `customer_id` is not NULL`.` product\_key is a foreign key to `Product` table.
+
+Table: `Product`
+
+    +-------------+---------+ 
+    | Column Name | Type    | 
+    +-------------+---------+ 
+    | product_key | int     | 
+    +-------------+---------+ 
+
+    product_key is the primary key column for this table.
+
+Write an SQL query to report the customer ids from the `Customer` table that bought all the products in the `Product` table.
+
+Return the result table in **any order**.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:** Customer table: 
+
+    +-------------+-------------+ 
+    | customer_id | product_key | 
+    +-------------+-------------+ 
+    | 1           | 5           | 
+    | 2           | 6           | 
+    | 3           | 5           | 
+    | 3           | 6           | 
+    | 1           | 6           | 
+    +-------------+-------------+ 
+
+Product table: 
+
+    +-------------+ 
+    | product_key | 
+    +-------------+ 
+    | 5           | 
+    | 6           | 
+    +-------------+
+
+**Output:** 
+
+    +-------------+ 
+    | customer_id | 
+    +-------------+ 
+    | 1           | 
+    | 3           | 
+    +-------------+
+
+**Explanation:** The customers who bought all the products (5 and 6) are customers with IDs 1 and 3. 

src/main/java/g1001_1100/s1045_customers_who_bought_all_products/readme.md

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+# Write your MySQL query statement below
+# #Medium #Database #2023_06_05_Time_1082_ms_(43.17%)_Space_0B_(100.00%)
+select customer_id
+from customer
+group by customer_id
+having count(distinct product_key)=(select count(*) from product);

src/main/java/g1001_1100/s1045_customers_who_bought_all_products/script.sql

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+package g0601_0700.s0602_friend_requests_ii_who_has_the_most_friends;
+
+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 RequestAccepted(requester_id INTEGER, accepter_id INTEGER, accept_date DATETIME); "
+                        + "INSERT INTO RequestAccepted(requester_id, accepter_id, accept_date)"
+                        + " VALUES (1, 2, '2016-06-03'); "
+                        + "INSERT INTO RequestAccepted(requester_id, accepter_id, accept_date)"
+                        + " VALUES (1, 3, '2016-06-08'); "
+                        + "INSERT INTO RequestAccepted(requester_id, accepter_id, accept_date)"
+                        + " VALUES (2, 3, '2016-06-08'); "
+                        + "INSERT INTO RequestAccepted(requester_id, accepter_id, accept_date)"
+                        + " VALUES (3, 4, '2016-06-09'); ")
+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/g0601_0700/"
+                                                                    + "s0602_friend_requests"
+                                                                    + "_ii_who_has_the_most_friends"
+                                                                    + "/script.sql"))
+                                            .lines()
+                                            .collect(Collectors.joining("\n"))
+                                            .replaceAll("#.*?\\r?\\n", ""))) {
+                assertThat(resultSet.next(), equalTo(true));
+                assertThat(resultSet.getInt(1), equalTo(3));
+                assertThat(resultSet.getInt(2), equalTo(3));
+                assertThat(resultSet.next(), equalTo(false));
+            }
+        }
+    }
+}

src/test/java/g0601_0700/s0602_friend_requests_ii_who_has_the_most_friends/MysqlTest.java

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+package g0601_0700.s0610_triangle_judgement;
+
+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 Triangle(x INTEGER, y INTEGER, z INTEGER); "
+                        + "INSERT INTO Triangle(x, y, z)"
+                        + " VALUES (13, 15, 30); "
+                        + "INSERT INTO Triangle(x, y, z)"
+                        + " VALUES (10, 20, 15); ")
+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/g0601_0700/"
+                                                                    + "s0610_triangle_judgement"
+                                                                    + "/script.sql"))
+                                            .lines()
+                                            .collect(Collectors.joining("\n"))
+                                            .replaceAll("#.*?\\r?\\n", ""))) {
+                assertThat(resultSet.next(), equalTo(true));
+                assertThat(resultSet.getInt(1), equalTo(13));
+                assertThat(resultSet.getInt(2), equalTo(15));
+                assertThat(resultSet.getInt(3), equalTo(30));
+                assertThat(resultSet.getNString(4), equalTo("No"));
+                assertThat(resultSet.next(), equalTo(true));
+                assertThat(resultSet.getInt(1), equalTo(10));
+                assertThat(resultSet.getInt(2), equalTo(20));
+                assertThat(resultSet.getInt(3), equalTo(15));
+                assertThat(resultSet.getNString(4), equalTo("Yes"));
+                assertThat(resultSet.next(), equalTo(false));
+            }
+        }
+    }
+}