src/main/java/hhn/temp/project/AssignmentManager.java

@@ -27,7 +27,7 @@ public class AssignmentManager {
         if (!workerMap.containsKey(workerId) || name == null || description == null) {
             throw new IllegalArgumentException("WorkerId must exist and name or description can't be null");
         }
-        Task task = new Task(++taskIdCounter, workerId, name, description, this);
+        Task task = new Task(++taskIdCounter, workerId, name, description);
         taskMap.put(taskIdCounter, task);
         return taskIdCounter;
     }

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

@@ -2,11 +2,13 @@ package hhn.temp.project.provider;
 
 import jdk.jshell.spi.ExecutionControl;
 
+import java.io.IOException;
+import java.sql.SQLException;
 import java.util.Collection;
 
 public interface DatabaseManager<E> extends Database {
-  public void saveObjects(Collection<E> objects);
+  public void saveObjects(Collection<E> objects) throws ExecutionControl.NotImplementedException, IOException, SQLException;
   public Collection<E> getObjects() throws ExecutionControl.NotImplementedException;
-  public void saveObject(E object) throws ExecutionControl.NotImplementedException;
+  public void saveObject(E object) throws ExecutionControl.NotImplementedException, IOException, SQLException;
   public E getObject(int id) throws ExecutionControl.NotImplementedException;
 }

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

@@ -1,34 +1,75 @@
 package hhn.temp.project.provider;
 
+import hhn.temp.project.Task;
+import hhn.temp.project.TaskState;
 import jdk.jshell.spi.ExecutionControl;
 
-import java.io.File;
 import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
 import java.sql.Connection;
 import java.sql.DriverManager;
+import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.Collection;
-import java.util.List;
 
 public class SimpleDatabaseManager<E> implements DatabaseManager<E> {
 
   private Connection connection;
 
-  @Override
-  public void saveObjects(Collection<E> objects) {
-
+  private enum QueryMode {
+    SELECT, INSERT, DELETE, UPDATE
   }
 
+  private int taskStateToInt(TaskState taskState) {
+    return (taskState == TaskState.FINISHED) ? 1 : 0;
+  }
+
+  private TaskState intToTaskState(int i) {
+    if (i < 0 || i > 1) {
+      throw new IllegalArgumentException("Integer may only bet 0 or 1");
+    }
+
+    return (i == 1) ? TaskState.FINISHED : TaskState.IN_PROGRESS;
+  }
+
+  private String getQuery(QueryMode query) throws IOException {
+    String queryString = null;
+
+    switch (query) {
+      case INSERT -> queryString = "INSERT INTO Task (name, description, workerid, taskstate) VALUES (?, ?, ?, ?)";
+      case UPDATE -> queryString = "UPDATE Task SET name = ?, description = ?, taskstate = ? WHERE taskid = ?";
+      case DELETE -> queryString = "DELETE FROM Task WHERE taskid = ?";
+      case SELECT -> queryString = "SELECT * FROM Task WHERE workerid = ?";
+    }
+
+    return queryString;
+  }
+
+  @Override
+  public void saveObjects(Collection<E> objects) throws IOException, SQLException {
+    for (E obj : objects) {
+      saveObject(obj);
+    }
+  }
+
+
   @Override
   public Collection<E> getObjects() throws ExecutionControl.NotImplementedException {
     throw new ExecutionControl.NotImplementedException("Not Implemented!");
   }
 
   @Override
-  public void saveObject(E object) throws ExecutionControl.NotImplementedException {
-    throw new ExecutionControl.NotImplementedException("Not Implemented!");
+  public void saveObject(E object) throws IOException, SQLException {
+    String query = getQuery(QueryMode.INSERT);
+
+    if (object instanceof Task task) {
+      try (PreparedStatement ps = connection.prepareStatement(query)) {
+        ps.setInt(1, task.getTaskId());
+        ps.setString(2, task.getName());
+        ps.setString(3, task.getDescription());
+        ps.setInt(4, task.getWorkerId());
+        ps.setInt(5, taskStateToInt(task.getTaskState()));
+      }
+    }
   }
 
   @Override

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

@@ -0,0 +1,7 @@
+CREATE TABLE Task (
+    taskid INT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(255) NOT NULL,
+    description TEXT,
+    workerid INT,
+    taskstate INT
+);

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

@@ -0,0 +1 @@
+DELETE FROM Task WHERE taskid = ?

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

@@ -0,0 +1 @@
+INSERT INTO Task (name, description, workerid, taskstate) VALUES (?, ?, ?, ?)

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

@@ -0,0 +1 @@
+SELECT * FROM Task WHERE workerid = ?

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

@@ -0,0 +1 @@
+UPDATE Task SET name = ?, description = ?, taskstate = ? WHERE taskid = ?

test/hhn/temp/project/DatabaseGoodCasesTest.java

@@ -27,6 +27,7 @@ public class DatabaseGoodCasesTest {
 
     databaseManager.connect();
     Task task = databaseManager.getObject(1);
+    databaseManager.close();
   }
 
   @Test
@@ -37,11 +38,13 @@ public class DatabaseGoodCasesTest {
 
     databaseManager.connect();
     databaseManager.saveObject(testTask);
+    databaseManager.close();
   }
 
   @Test
   @DisplayName("Assert connecting to database")
   public void assertConnectToDatabase() throws SQLException, IOException {
     databaseManager.connect();
+    databaseManager.close();
   }
 }