src/main/java/hhn/temp/project/provider/SimpleDatabaseManager.java

@@ -65,7 +65,7 @@ public class SimpleDatabaseManager<E> implements DatabaseManager<E> {
     String query = getQuery(QueryMode.INSERT);
 
     if (object instanceof Task task) {
-      try (PreparedStatement ps = connection.prepareStatement(query)) {
+      PreparedStatement ps = connection.prepareStatement(query);
       ps.setInt(1, task.getTaskId());
       ps.setString(2, task.getName());
       ps.setString(3, task.getDescription());
@@ -75,7 +75,6 @@ public class SimpleDatabaseManager<E> implements DatabaseManager<E> {
       ps.executeUpdate();
     }
   }
-  }
 
   @Override
   public E getObject(int taskId) throws SQLException {
@@ -113,6 +112,29 @@ public class SimpleDatabaseManager<E> implements DatabaseManager<E> {
 
   @Override
   public E updateObject(int taskId, E object) throws SQLException {
+    String query = getQuery(QueryMode.UPDATE);
+
+    if (object instanceof Task task) {
+
+      if (taskId != task.getTaskId()) {
+        throw new IllegalArgumentException("Task ID does not equals Task ID from Task!");
+      }
+
+      PreparedStatement ps = connection.prepareStatement(query);
+      ps.setString(1, task.getName());
+      ps.setString(2, task.getDescription());
+      ps.setInt(3, taskStateToInt(task.getTaskState()));
+      ps.setInt(4, task.getTaskId());
+
+      int updated = ps.executeUpdate();
+
+      if (updated == 0) {
+        return null;
+      }
+
+      return (E) task;
+    }
+
     return null;
   }
 

src/main/java/hhn/temp/project/provider/sql/createTaskTable.sql

@@ -1,5 +1,6 @@
 CREATE TABLE Task (
-    taskid INT AUTO_INCREMENT PRIMARY KEY,
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    taskid INT,
     name VARCHAR(255) NOT NULL,
     description TEXT,
     workerid INT,

test/hhn/temp/project/DatabaseBadCasesTest.java

@@ -43,6 +43,6 @@ public class DatabaseBadCasesTest {
   @Test
   @DisplayName("Updates an object that does not exist")
   public void assertUpdateNonExistentObject() throws SQLException {
-    assertNull(databaseManager.updateObject(123, new Task(1, 2, "", "")));
+    assertNull(databaseManager.updateObject(123, new Task(123, 2, "", "")));
   }
 }