diff --git a/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java b/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java
index 91f902c..632e21e 100644
--- a/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java
+++ b/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java
@@ -1,7 +1,9 @@
 package de.hitec.nhplus.datastorage;
 
-import java.sql.*;
-import java.util.ArrayList;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
 import java.util.List;
 
 public abstract class DaoImp<T> implements Dao<T> {
@@ -45,13 +47,13 @@ public abstract class DaoImp<T> implements Dao<T> {
 
     protected abstract List<T> getListFromResultSet(ResultSet result) throws SQLException;
 
-    protected abstract PreparedStatement getCreateStatement(T t);
+    protected abstract PreparedStatement getCreateStatement(T t) throws SQLException;
 
-    protected abstract PreparedStatement getReadByIDStatement(int id);
+    protected abstract PreparedStatement getReadByIDStatement(int id) throws SQLException;
 
-    protected abstract PreparedStatement getReadAllStatement();
+    protected abstract PreparedStatement getReadAllStatement() throws SQLException;
 
-    protected abstract PreparedStatement getUpdateStatement(T t);
+    protected abstract PreparedStatement getUpdateStatement(T t) throws SQLException;
 
-    protected abstract PreparedStatement getDeleteStatement(int id);
+    protected abstract PreparedStatement getDeleteStatement(int id) throws SQLException;
 }
diff --git a/src/main/java/de/hitec/nhplus/fixtures/TreatmentFixture.java b/src/main/java/de/hitec/nhplus/fixtures/TreatmentFixture.java
index 2e418e9..e63aef4 100644
--- a/src/main/java/de/hitec/nhplus/fixtures/TreatmentFixture.java
+++ b/src/main/java/de/hitec/nhplus/fixtures/TreatmentFixture.java
@@ -1,9 +1,9 @@
 package de.hitec.nhplus.fixtures;
 
 import de.hitec.nhplus.datastorage.DaoFactory;
-import de.hitec.nhplus.treatment.TreatmentDao;
 import de.hitec.nhplus.patient.Patient;
 import de.hitec.nhplus.treatment.Treatment;
+import de.hitec.nhplus.treatment.TreatmentDao;
 
 import java.sql.Connection;
 import java.sql.SQLException;
@@ -16,53 +16,44 @@ import java.util.Map;
 import static de.hitec.nhplus.utils.DateConverter.convertStringToLocalDate;
 import static de.hitec.nhplus.utils.DateConverter.convertStringToLocalTime;
 
-public class TreatmentFixture implements Fixture<Treatment>
-{
+public class TreatmentFixture implements Fixture<Treatment> {
     private final Map<String, Patient> patientsByName;
 
-    public TreatmentFixture(Map<String, Patient> patientsByName)
-    {
+    public TreatmentFixture(Map<String, Patient> patientsByName) {
         this.patientsByName = patientsByName;
     }
 
     @Override
-    public void dropTable(Connection connection)
-    {
-        try (Statement statement = connection.createStatement())
-        {
+    public void dropTable(Connection connection) {
+        try (Statement statement = connection.createStatement()) {
             statement.execute("DROP TABLE treatment");
-        } catch (SQLException exception)
-        {
+        } catch (SQLException exception) {
             System.out.println(exception.getMessage());
         }
     }
 
     @Override
-    public void setupTable(Connection connection)
-    {
+    public void setupTable(Connection connection) {
         final String SQL = "CREATE TABLE IF NOT EXISTS treatment (" +
-            "   id INTEGER PRIMARY KEY AUTOINCREMENT, " +
-            "   patientId INTEGER NOT NULL, " +
-            "   treatment_date TEXT NOT NULL, " +
-            "   begin TEXT NOT NULL, " +
-            "   end TEXT NOT NULL, " +
-            "   description TEXT NOT NULL, " +
-            "   remark TEXT NOT NULL," +
-            "   FOREIGN KEY (patientId) REFERENCES patient (id) ON DELETE CASCADE " +
-            ");";
+                "   id INTEGER PRIMARY KEY AUTOINCREMENT, " +
+                "   patientId INTEGER NOT NULL, " +
+                "   treatment_date TEXT NOT NULL, " +
+                "   begin TEXT NOT NULL, " +
+                "   end TEXT NOT NULL, " +
+                "   description TEXT NOT NULL, " +
+                "   remark TEXT NOT NULL," +
+                "   FOREIGN KEY (patientId) REFERENCES patient (id) ON DELETE CASCADE " +
+                ");";
 
-        try (Statement statement = connection.createStatement())
-        {
+        try (Statement statement = connection.createStatement()) {
             statement.execute(SQL);
-        } catch (SQLException exception)
-        {
+        } catch (SQLException exception) {
             System.out.println(exception.getMessage());
         }
     }
 
     @Override
-    public Map<String, Treatment> load() throws SQLException
-    {
+    public Map<String, Treatment> load() throws SQLException {
         List<Treatment> treatments = new ArrayList<>();
 
         Patient seppl = patientsByName.get("Seppl");
@@ -72,102 +63,102 @@ public class TreatmentFixture implements Fixture<Treatment>
         Patient elisabeth = patientsByName.get("Elisabeth");
 
         treatments.add(new Treatment(
-            1,
-            seppl.getId(),
-            convertStringToLocalDate("2023-06-03"),
-            convertStringToLocalTime("11:00"),
-            convertStringToLocalTime("15:00"),
-            "Gespräch",
-            "Der Patient hat enorme Angstgefühle und glaubt, er sei überfallen worden."
-                + "Ihm seien alle Wertsachen gestohlen worden."
-                + "Patient beruhigt sich erst, als alle Wertsachen im Zimmer gefunden worden sind."
+                1,
+                seppl,
+                convertStringToLocalDate("2023-06-03"),
+                convertStringToLocalTime("11:00"),
+                convertStringToLocalTime("15:00"),
+                "Gespräch",
+                "Der Patient hat enorme Angstgefühle und glaubt, er sei überfallen worden."
+                        + "Ihm seien alle Wertsachen gestohlen worden."
+                        + "Patient beruhigt sich erst, als alle Wertsachen im Zimmer gefunden worden sind."
         ));
         treatments.add(new Treatment(
-            2,
-            seppl.getId(),
-            convertStringToLocalDate("2023-06-05"),
-            convertStringToLocalTime("11:00"),
-            convertStringToLocalTime("12:30"),
-            "Gespräch",
-            "Patient irrt auf der Suche nach gestohlenen Wertsachen durch die Etage "
-                + "und bezichtigt andere Bewohner des Diebstahls."
-                + "Patient wird in seinen Raum zurückbegleitet und erhält Beruhigungsmittel."
+                2,
+                seppl,
+                convertStringToLocalDate("2023-06-05"),
+                convertStringToLocalTime("11:00"),
+                convertStringToLocalTime("12:30"),
+                "Gespräch",
+                "Patient irrt auf der Suche nach gestohlenen Wertsachen durch die Etage "
+                        + "und bezichtigt andere Bewohner des Diebstahls."
+                        + "Patient wird in seinen Raum zurückbegleitet und erhält Beruhigungsmittel."
         ));
         treatments.add(new Treatment(
-            3,
-            martina.getId(),
-            convertStringToLocalDate("2023-06-04"),
-            convertStringToLocalTime("07:30"),
-            convertStringToLocalTime("08:00"),
-            "Waschen",
-            "Patient mit Waschlappen gewaschen und frisch angezogen. Patient gewendet."
+                3,
+                martina,
+                convertStringToLocalDate("2023-06-04"),
+                convertStringToLocalTime("07:30"),
+                convertStringToLocalTime("08:00"),
+                "Waschen",
+                "Patient mit Waschlappen gewaschen und frisch angezogen. Patient gewendet."
         ));
         treatments.add(new Treatment(
-            4,
-            seppl.getId(),
-            convertStringToLocalDate("2023-06-06"),
-            convertStringToLocalTime("15:10"),
-            convertStringToLocalTime("16:00"),
-            "Spaziergang",
-            "Spaziergang im Park, Patient döst  im Rollstuhl ein")
+                4,
+                seppl,
+                convertStringToLocalDate("2023-06-06"),
+                convertStringToLocalTime("15:10"),
+                convertStringToLocalTime("16:00"),
+                "Spaziergang",
+                "Spaziergang im Park, Patient döst  im Rollstuhl ein")
         );
         treatments.add(new Treatment(
-            8,
-            seppl.getId(),
-            convertStringToLocalDate("2023-06-08"),
-            convertStringToLocalTime("15:00"),
-            convertStringToLocalTime("16:00"),
-            "Spaziergang",
-            "Parkspaziergang; Patient ist heute lebhafter und hat klare Momente; erzählt von seiner Tochter")
+                8,
+                seppl,
+                convertStringToLocalDate("2023-06-08"),
+                convertStringToLocalTime("15:00"),
+                convertStringToLocalTime("16:00"),
+                "Spaziergang",
+                "Parkspaziergang; Patient ist heute lebhafter und hat klare Momente; erzählt von seiner Tochter")
         );
         treatments.add(new Treatment(
-            9,
-            martina.getId(),
-            convertStringToLocalDate("2023-06-07"),
-            convertStringToLocalTime("11:00"),
-            convertStringToLocalTime("11:30"),
-            "Waschen",
-            "Waschen per Dusche auf einem Stuhl; Patientin gewendet;")
+                9,
+                martina,
+                convertStringToLocalDate("2023-06-07"),
+                convertStringToLocalTime("11:00"),
+                convertStringToLocalTime("11:30"),
+                "Waschen",
+                "Waschen per Dusche auf einem Stuhl; Patientin gewendet;")
         );
         treatments.add(new Treatment(
-            12,
-            hans.getId(),
-            convertStringToLocalDate("2023-06-08"),
-            convertStringToLocalTime("15:00"),
-            convertStringToLocalTime("15:30"),
-            "Physiotherapie",
-            "Übungen zur Stabilisation und Mobilisierung der Rückenmuskulatur")
+                12,
+                hans,
+                convertStringToLocalDate("2023-06-08"),
+                convertStringToLocalTime("15:00"),
+                convertStringToLocalTime("15:30"),
+                "Physiotherapie",
+                "Übungen zur Stabilisation und Mobilisierung der Rückenmuskulatur")
         );
         treatments.add(new Treatment(
-            14,
-            ahmet.getId(),
-            convertStringToLocalDate("2023-08-24"),
-            convertStringToLocalTime("09:30"),
-            convertStringToLocalTime("10:15"),
-            "KG",
-            "Lympfdrainage"));
+                14,
+                ahmet,
+                convertStringToLocalDate("2023-08-24"),
+                convertStringToLocalTime("09:30"),
+                convertStringToLocalTime("10:15"),
+                "KG",
+                "Lympfdrainage"));
         treatments.add(new Treatment(
-            16,
-            elisabeth.getId(),
-            convertStringToLocalDate("2023-08-31"),
-            convertStringToLocalTime("13:30"),
-            convertStringToLocalTime("13:45"),
-            "Toilettengang",
-            "Hilfe beim Toilettengang; Patientin klagt über Schmerzen beim Stuhlgang. Gabe von Iberogast")
+                16,
+                elisabeth,
+                convertStringToLocalDate("2023-08-31"),
+                convertStringToLocalTime("13:30"),
+                convertStringToLocalTime("13:45"),
+                "Toilettengang",
+                "Hilfe beim Toilettengang; Patientin klagt über Schmerzen beim Stuhlgang. Gabe von Iberogast")
         );
         treatments.add(new Treatment(
-            17,
-            elisabeth.getId(),
-            convertStringToLocalDate("2023-09-01"),
-            convertStringToLocalTime("16:00"),
-            convertStringToLocalTime("17:00"),
-            "KG",
-            "Massage der Extremitäten zur Verbesserung der Durchblutung")
+                17,
+                elisabeth,
+                convertStringToLocalDate("2023-09-01"),
+                convertStringToLocalTime("16:00"),
+                convertStringToLocalTime("17:00"),
+                "KG",
+                "Massage der Extremitäten zur Verbesserung der Durchblutung")
         );
 
         TreatmentDao dao = DaoFactory.getInstance().createTreatmentDao();
         Map<String, Treatment> treatmentsById = new HashMap<>();
-        for (Treatment treatment : treatments){
+        for (Treatment treatment : treatments) {
             dao.create(treatment);
             treatmentsById.put(String.valueOf(treatment.getId()), treatment);
         }
diff --git a/src/main/java/de/hitec/nhplus/nurse/NurseDao.java b/src/main/java/de/hitec/nhplus/nurse/NurseDao.java
index f7bbbc6..1af8329 100644
--- a/src/main/java/de/hitec/nhplus/nurse/NurseDao.java
+++ b/src/main/java/de/hitec/nhplus/nurse/NurseDao.java
@@ -15,31 +15,21 @@ public class NurseDao extends DaoImp<Nurse> {
     }
 
     @Override
-    protected PreparedStatement getCreateStatement(Nurse nurse) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "INSERT INTO nurse (firstname, surname, phoneNumber)" +
-                    "VALUES (?, ?, ?)";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setString(1, nurse.getFirstName());
-            preparedStatement.setString(2, nurse.getSurname());
-            preparedStatement.setString(3, nurse.getPhoneNumber());
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getCreateStatement(Nurse nurse) throws SQLException {
+        final String SQL = "INSERT INTO nurse (firstname, surname, phoneNumber)" +
+                "VALUES (?, ?, ?)";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setString(1, nurse.getFirstName());
+        preparedStatement.setString(2, nurse.getSurname());
+        preparedStatement.setString(3, nurse.getPhoneNumber());
         return preparedStatement;
     }
 
     @Override
-    protected PreparedStatement getReadByIDStatement(int id) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "SELECT * FROM nurse WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, id);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getReadByIDStatement(int id) throws SQLException {
+        final String SQL = "SELECT * FROM nurse WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, id);
         return preparedStatement;
     }
 
@@ -54,63 +44,42 @@ public class NurseDao extends DaoImp<Nurse> {
     }
 
     @Override
-    protected PreparedStatement getReadAllStatement() {
-        PreparedStatement statement = null;
-        try {
-            final String SQL = "SELECT * FROM nurse";
-            statement = this.connection.prepareStatement(SQL);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
-        return statement;
+    protected PreparedStatement getReadAllStatement() throws SQLException {
+        final String SQL = "SELECT * FROM nurse";
+        return this.connection.prepareStatement(SQL);
     }
 
     @Override
     protected List<Nurse> getListFromResultSet(ResultSet result) throws SQLException {
         ArrayList<Nurse> list = new ArrayList<>();
         while (result.next()) {
-            list.add(new Nurse(
-                    result.getInt(1),
-                    result.getString(2),
-                    result.getString(3),
-                    result.getString(4)
-            ));
+            list.add(getInstanceFromResultSet(result));
         }
         return list;
     }
 
 
     @Override
-    protected PreparedStatement getUpdateStatement(Nurse nurse) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL =
-                    "UPDATE nurse SET " +
-                            "firstname = ?, " +
-                            "surname = ?, " +
-                            "phoneNumber = ?, " +
-                            "WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setString(1, nurse.getFirstName());
-            preparedStatement.setString(2, nurse.getSurname());
-            preparedStatement.setString(3, nurse.getPhoneNumber());
-            preparedStatement.setInt(4, nurse.getId());
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getUpdateStatement(Nurse nurse) throws SQLException {
+        final String SQL =
+                "UPDATE nurse SET " +
+                        "firstname = ?, " +
+                        "surname = ?, " +
+                        "phoneNumber = ? " +
+                        "WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setString(1, nurse.getFirstName());
+        preparedStatement.setString(2, nurse.getSurname());
+        preparedStatement.setString(3, nurse.getPhoneNumber());
+        preparedStatement.setInt(4, nurse.getId());
         return preparedStatement;
     }
 
     @Override
-    protected PreparedStatement getDeleteStatement(int id) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "DELETE FROM nurse WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, id);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getDeleteStatement(int id) throws SQLException {
+        final String SQL = "DELETE FROM nurse WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, id);
         return preparedStatement;
     }
 }
diff --git a/src/main/java/de/hitec/nhplus/patient/PatientDao.java b/src/main/java/de/hitec/nhplus/patient/PatientDao.java
index 0648164..a4a779f 100644
--- a/src/main/java/de/hitec/nhplus/patient/PatientDao.java
+++ b/src/main/java/de/hitec/nhplus/patient/PatientDao.java
@@ -17,33 +17,23 @@ public class PatientDao extends DaoImp<Patient> {
     }
 
     @Override
-    protected PreparedStatement getCreateStatement(Patient patient) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "INSERT INTO patient (firstname, surname, dateOfBirth, carelevel, roomnumber) " +
-                    "VALUES (?, ?, ?, ?, ?)";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setString(1, patient.getFirstName());
-            preparedStatement.setString(2, patient.getSurname());
-            preparedStatement.setString(3, patient.getDateOfBirth());
-            preparedStatement.setString(4, patient.getCareLevel());
-            preparedStatement.setString(5, patient.getRoomNumber());
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getCreateStatement(Patient patient) throws SQLException {
+        final String SQL = "INSERT INTO patient (firstname, surname, dateOfBirth, carelevel, roomnumber) " +
+                "VALUES (?, ?, ?, ?, ?)";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setString(1, patient.getFirstName());
+        preparedStatement.setString(2, patient.getSurname());
+        preparedStatement.setString(3, patient.getDateOfBirth());
+        preparedStatement.setString(4, patient.getCareLevel());
+        preparedStatement.setString(5, patient.getRoomNumber());
         return preparedStatement;
     }
 
     @Override
-    protected PreparedStatement getReadByIDStatement(int id) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "SELECT * FROM patient WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, id);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getReadByIDStatement(int id) throws SQLException {
+        final String SQL = "SELECT * FROM patient WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, id);
         return preparedStatement;
     }
 
@@ -59,68 +49,45 @@ public class PatientDao extends DaoImp<Patient> {
     }
 
     @Override
-    protected PreparedStatement getReadAllStatement() {
-        PreparedStatement statement = null;
-        try {
-            final String SQL = "SELECT * FROM patient";
-            statement = this.connection.prepareStatement(SQL);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
-        return statement;
+    protected PreparedStatement getReadAllStatement() throws SQLException {
+        final String SQL = "SELECT * FROM patient";
+        return this.connection.prepareStatement(SQL);
     }
 
     @Override
     protected List<Patient> getListFromResultSet(ResultSet result) throws SQLException {
         ArrayList<Patient> list = new ArrayList<>();
         while (result.next()) {
-            Patient patient = new Patient(
-                    result.getInt(1),
-                    result.getString(2),
-                    result.getString(3),
-                    DateConverter.convertStringToLocalDate(result.getString(4)),
-                    result.getString(5),
-                    result.getString(6));
-            list.add(patient);
+            list.add(getInstanceFromResultSet(result));
         }
         return list;
     }
 
     @Override
-    protected PreparedStatement getUpdateStatement(Patient patient) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL =
-                    "UPDATE patient SET " +
-                            "firstname = ?, " +
-                            "surname = ?, " +
-                            "dateOfBirth = ?, " +
-                            "carelevel = ?, " +
-                            "roomnumber = ?, " +
-                            "WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setString(1, patient.getFirstName());
-            preparedStatement.setString(2, patient.getSurname());
-            preparedStatement.setString(3, patient.getDateOfBirth());
-            preparedStatement.setString(4, patient.getCareLevel());
-            preparedStatement.setString(5, patient.getRoomNumber());
-            preparedStatement.setInt(6, patient.getId());
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getUpdateStatement(Patient patient) throws SQLException {
+        final String SQL =
+                "UPDATE patient SET " +
+                        "firstname = ?, " +
+                        "surname = ?, " +
+                        "dateOfBirth = ?, " +
+                        "carelevel = ?, " +
+                        "roomnumber = ?, " +
+                        "WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setString(1, patient.getFirstName());
+        preparedStatement.setString(2, patient.getSurname());
+        preparedStatement.setString(3, patient.getDateOfBirth());
+        preparedStatement.setString(4, patient.getCareLevel());
+        preparedStatement.setString(5, patient.getRoomNumber());
+        preparedStatement.setInt(6, patient.getId());
         return preparedStatement;
     }
 
     @Override
-    protected PreparedStatement getDeleteStatement(int id) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "DELETE FROM patient WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, id);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getDeleteStatement(int id) throws SQLException {
+        final String SQL = "DELETE FROM patient WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, id);
         return preparedStatement;
     }
 }
diff --git a/src/main/java/de/hitec/nhplus/treatment/TreatmentDao.java b/src/main/java/de/hitec/nhplus/treatment/TreatmentDao.java
index 3521e7e..710b6ad 100644
--- a/src/main/java/de/hitec/nhplus/treatment/TreatmentDao.java
+++ b/src/main/java/de/hitec/nhplus/treatment/TreatmentDao.java
@@ -18,34 +18,24 @@ public class TreatmentDao extends DaoImp<Treatment> {
     }
 
     @Override
-    protected PreparedStatement getCreateStatement(Treatment treatment) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "INSERT INTO treatment (patientId, treatment_date, begin, end, description, remark) " +
-                    "VALUES (?, ?, ?, ?, ?, ?)";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, treatment.getPatient().getId());
-            preparedStatement.setString(2, treatment.getDate());
-            preparedStatement.setString(3, treatment.getBegin());
-            preparedStatement.setString(4, treatment.getEnd());
-            preparedStatement.setString(5, treatment.getDescription());
-            preparedStatement.setString(6, treatment.getRemarks());
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getCreateStatement(Treatment treatment) throws SQLException {
+        final String SQL = "INSERT INTO treatment (patientId, treatment_date, begin, end, description, remark) " +
+                "VALUES (?, ?, ?, ?, ?, ?)";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, treatment.getPatient().getId());
+        preparedStatement.setString(2, treatment.getDate());
+        preparedStatement.setString(3, treatment.getBegin());
+        preparedStatement.setString(4, treatment.getEnd());
+        preparedStatement.setString(5, treatment.getDescription());
+        preparedStatement.setString(6, treatment.getRemarks());
         return preparedStatement;
     }
 
     @Override
-    protected PreparedStatement getReadByIDStatement(int id) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "SELECT * FROM treatment WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, id);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getReadByIDStatement(int id) throws SQLException {
+        final String SQL = "SELECT * FROM treatment WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, id);
         return preparedStatement;
     }
 
@@ -63,15 +53,9 @@ public class TreatmentDao extends DaoImp<Treatment> {
     }
 
     @Override
-    protected PreparedStatement getReadAllStatement() {
-        PreparedStatement statement = null;
-        try {
-            final String SQL = "SELECT * FROM treatment";
-            statement = this.connection.prepareStatement(SQL);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
-        return statement;
+    protected PreparedStatement getReadAllStatement() throws SQLException {
+        final String SQL = "SELECT * FROM treatment";
+        return this.connection.prepareStatement(SQL);
     }
 
     @Override
@@ -83,15 +67,10 @@ public class TreatmentDao extends DaoImp<Treatment> {
         return list;
     }
 
-    private PreparedStatement getReadAllTreatmentsOfOnePatientByPid(int patientId) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL = "SELECT * FROM treatment WHERE patientId = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, patientId);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    private PreparedStatement getReadAllTreatmentsOfOnePatientByPid(int patientId) throws SQLException {
+        final String SQL = "SELECT * FROM treatment WHERE patientId = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, patientId);
         return preparedStatement;
     }
 
@@ -101,43 +80,33 @@ public class TreatmentDao extends DaoImp<Treatment> {
     }
 
     @Override
-    protected PreparedStatement getUpdateStatement(Treatment treatment) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL =
-                    "UPDATE treatment SET " +
-                            "patientId = ?, " +
-                            "treatment_date = ?, " +
-                            "begin = ?, " +
-                            "end = ?, " +
-                            "description = ?, " +
-                            "remark = ? " +
-                            "WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, treatment.getPatient().getId());
-            preparedStatement.setString(2, treatment.getDate());
-            preparedStatement.setString(3, treatment.getBegin());
-            preparedStatement.setString(4, treatment.getEnd());
-            preparedStatement.setString(5, treatment.getDescription());
-            preparedStatement.setString(6, treatment.getRemarks());
-            preparedStatement.setInt(7, treatment.getId());
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getUpdateStatement(Treatment treatment) throws SQLException {
+        final String SQL =
+                "UPDATE treatment SET " +
+                        "patientId = ?, " +
+                        "treatment_date = ?, " +
+                        "begin = ?, " +
+                        "end = ?, " +
+                        "description = ?, " +
+                        "remark = ? " +
+                        "WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, treatment.getPatient().getId());
+        preparedStatement.setString(2, treatment.getDate());
+        preparedStatement.setString(3, treatment.getBegin());
+        preparedStatement.setString(4, treatment.getEnd());
+        preparedStatement.setString(5, treatment.getDescription());
+        preparedStatement.setString(6, treatment.getRemarks());
+        preparedStatement.setInt(7, treatment.getId());
         return preparedStatement;
     }
 
     @Override
-    protected PreparedStatement getDeleteStatement(int id) {
-        PreparedStatement preparedStatement = null;
-        try {
-            final String SQL =
-                    "DELETE FROM treatment WHERE id = ?";
-            preparedStatement = this.connection.prepareStatement(SQL);
-            preparedStatement.setInt(1, id);
-        } catch (SQLException exception) {
-            exception.printStackTrace();
-        }
+    protected PreparedStatement getDeleteStatement(int id) throws SQLException {
+        final String SQL =
+                "DELETE FROM treatment WHERE id = ?";
+        PreparedStatement preparedStatement = this.connection.prepareStatement(SQL);
+        preparedStatement.setInt(1, id);
         return preparedStatement;
     }
 }
diff --git a/src/main/java/de/hitec/nhplus/treatment/TreatmentModalController.java b/src/main/java/de/hitec/nhplus/treatment/TreatmentModalController.java
index 2d61fae..f6e4927 100644
--- a/src/main/java/de/hitec/nhplus/treatment/TreatmentModalController.java
+++ b/src/main/java/de/hitec/nhplus/treatment/TreatmentModalController.java
@@ -44,7 +44,7 @@ public class TreatmentModalController {
             isNewTreatment = true;
             LocalTime currentTime = LocalTime.now();
             this.treatment = new Treatment(
-                    patient.getId(),
+                    patient,
                     LocalDate.now(),
                     LocalTime.of(currentTime.getHour(), currentTime.getMinute()),
                     LocalTime.of(currentTime.getHour(), currentTime.getMinute()),