diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/ResultSet.java b/src/main/java/dev/pcvolkmer/onco/datamapper/ResultSet.java
new file mode 100644
index 0000000..013bc1a
--- /dev/null
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/ResultSet.java
@@ -0,0 +1,82 @@
+package dev.pcvolkmer.onco.datamapper;
+
+import java.sql.Date;
+import java.util.Map;
+
+/**
+ * Result set type to wrap <code>Map<String, Object></code>
+ *
+ * @author Paul-Christian Volkmer
+ * @since 0.1
+ */
+public class ResultSet {
+
+    private final Map<String, Object> rawData;
+
+    private ResultSet(final Map<String, Object> rawData) {
+        this.rawData = rawData;
+    }
+
+    public static ResultSet from(final Map<String, Object> rawData) {
+        return new ResultSet(rawData);
+    }
+
+    public Map<String, Object> getRawData() {
+        return rawData;
+    }
+
+    /**
+     * Get column value as String and cast value if possible
+     * @param columnName The name of the column
+     * @return The column value as String
+     */
+    public String getString(String columnName) {
+        var raw = this.rawData.get(columnName);
+
+        if (raw == null) {
+            return null;
+        } else if (raw instanceof String) {
+            return raw.toString();
+        } else if (raw instanceof Integer) {
+            return ((Integer) raw).toString();
+        }
+
+        throw new IllegalArgumentException("Cannot convert " + raw.getClass() + " to String");
+    }
+
+    /**
+     * Get column value as Integer and cast value if possible
+     * @param columnName The name of the column
+     * @return The column value as Integer
+     */
+    public Integer getInteger(String columnName) {
+        var raw = this.rawData.get(columnName);
+
+        if (raw == null) {
+            return null;
+        } else if (raw instanceof Integer) {
+            return ((Integer) raw);
+        }
+
+        throw new IllegalArgumentException("Cannot convert " + raw.getClass() + " to Integer");
+    }
+
+    /**
+     * Get column value as Date and cast value if possible
+     * @param columnName The name of the column
+     * @return The column value as Date
+     */
+    public Date getDate(String columnName) {
+        var raw = this.rawData.get(columnName);
+
+        if (raw == null) {
+            return null;
+        }
+        if (raw instanceof Date) {
+            return (Date) raw;
+        }
+
+        throw new IllegalArgumentException("Cannot convert " + raw.getClass() + " to Date");
+    }
+
+}
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/TypeMapper.java b/src/main/java/dev/pcvolkmer/onco/datamapper/TypeMapper.java
deleted file mode 100644
index b99bfe0..0000000
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/TypeMapper.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package dev.pcvolkmer.onco.datamapper;
-
-import java.sql.Date;
-
-public class TypeMapper {
-
-    public static String asString(Object raw) {
-        if (raw == null) {
-            return null;
-        }
-        if (raw instanceof String) {
-            return (String) raw;
-        } else if (raw instanceof Integer) {
-            return ((Integer) raw).toString();
-        }
-
-        throw new IllegalArgumentException("Cannot convert " + raw.getClass() + " to String");
-    }
-
-    public static Date asDate(Object raw) {
-        if (raw == null) {
-            return null;
-        }
-        if (raw instanceof Date) {
-            return (Date) raw;
-        }
-
-        throw new IllegalArgumentException("Cannot convert " + raw.getClass() + " to Date");
-    }
-
-}
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractDataCatalogue.java b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractDataCatalogue.java
index 533859b..a500125 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractDataCatalogue.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractDataCatalogue.java
@@ -1,5 +1,6 @@
 package dev.pcvolkmer.onco.datamapper.datacatalogues;
 
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.exceptions.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
 
@@ -28,7 +29,7 @@ public abstract class AbstractDataCatalogue implements DataCatalogue {
      * @return The procedure id
      */
     @Override
-    public Map<String, Object> getById(int id) {
+    public ResultSet getById(int id) {
         var result = this.jdbcTemplate.queryForList(
                 String.format(
                         "SELECT * FROM %s JOIN prozedur ON (prozedur.id = %s.id) WHERE geloescht = 0 AND prozedur.id = ?",
@@ -43,7 +44,7 @@ public abstract class AbstractDataCatalogue implements DataCatalogue {
             throw new DataAccessException("Multiple records found for id: " + id);
         }
 
-        return result.get(0);
+        return ResultSet.from(result.get(0));
     }
 
 }
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractSubformDataCatalogue.java b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractSubformDataCatalogue.java
index eb7dd02..581a72b 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractSubformDataCatalogue.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/AbstractSubformDataCatalogue.java
@@ -1,9 +1,10 @@
 package dev.pcvolkmer.onco.datamapper.datacatalogues;
 
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import org.springframework.jdbc.core.JdbcTemplate;
 
 import java.util.List;
-import java.util.Map;
+import java.util.stream.Collectors;
 
 /**
  * Common implementations for all data catalogues used in subforms
@@ -25,14 +26,17 @@ public abstract class AbstractSubformDataCatalogue extends AbstractDataCatalogue
      * @param id The procedure id
      * @return The procedure id
      */
-    public List<Map<String, Object>> getAllByMainId(int id) {
+    public List<ResultSet> getAllByMainId(int id) {
         return this.jdbcTemplate.queryForList(
-                String.format(
-                        "SELECT * FROM %s JOIN prozedur ON (prozedur.id = %s.id) WHERE geloescht = 0 AND hauptprozedur_id = ?",
-                        getTableName(),
-                        getTableName()
-                ),
-                id);
+                        String.format(
+                                "SELECT * FROM %s JOIN prozedur ON (prozedur.id = %s.id) WHERE geloescht = 0 AND hauptprozedur_id = ?",
+                                getTableName(),
+                                getTableName()
+                        ),
+                        id)
+                .stream()
+                .map(ResultSet::from)
+                .collect(Collectors.toList());
     }
 
 }
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/DataCatalogue.java b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/DataCatalogue.java
index 4b1610d..adc5bd3 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/DataCatalogue.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/DataCatalogue.java
@@ -1,6 +1,6 @@
 package dev.pcvolkmer.onco.datamapper.datacatalogues;
 
-import java.util.Map;
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 
 /**
  * Common interface for all data catalogues
@@ -15,6 +15,6 @@ public interface DataCatalogue {
      * @param id The database id (primary key)
      * @return The result set
      */
-    Map<String, Object> getById(int id);
+    ResultSet getById(int id);
 
 }
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/PatientCatalogue.java b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/PatientCatalogue.java
index 1021321..5c3f15b 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/PatientCatalogue.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/datacatalogues/PatientCatalogue.java
@@ -1,10 +1,9 @@
 package dev.pcvolkmer.onco.datamapper.datacatalogues;
 
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.exceptions.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
 
-import java.util.Map;
-
 /**
  * Load raw result sets from database table 'patient'
  *
@@ -25,11 +24,12 @@ public class PatientCatalogue implements DataCatalogue {
 
     /**
      * Get patient result set by procedure id
+     *
      * @param id The procedure id
      * @return The procedure id
      */
     @Override
-    public Map<String, Object> getById(int id) {
+    public ResultSet getById(int id) {
 
         var result = this.jdbcTemplate.queryForList(
                 "SELECT * FROM patient WHERE id = ?",
@@ -41,7 +41,7 @@ public class PatientCatalogue implements DataCatalogue {
             throw new DataAccessException("Multiple patient records found for id: " + id);
         }
 
-        return result.get(0);
+        return ResultSet.from(result.get(0));
     }
 
 }
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapper.java b/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapper.java
index 9c23dfb..fb01bb9 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapper.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapper.java
@@ -4,8 +4,6 @@ import dev.pcvolkmer.mv64e.mtb.Coding;
 import dev.pcvolkmer.mv64e.mtb.MtbDiagnosis;
 import dev.pcvolkmer.onco.datamapper.datacatalogues.KpaCatalogue;
 
-import static dev.pcvolkmer.onco.datamapper.TypeMapper.asString;
-
 /**
  * Mapper class to load and map diagnosis data from database table 'dk_dnpm_kpa'
  *
@@ -30,12 +28,12 @@ public class KpaDiagnosisDataMapper implements DataMapper<MtbDiagnosis> {
     public MtbDiagnosis getById(int id) {
         var data = kpaCatalogue.getById(id);
 
-        var builder =  MtbDiagnosis.builder();
+        var builder = MtbDiagnosis.builder();
         builder
-                .id(asString(data.get("id")))
+                .id(data.getString("id"))
                 .code(
                         Coding.builder()
-                                .code(asString(data.get("icd10")))
+                                .code(data.getString("icd10"))
                                 .build()
                 );
         return builder.build();
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapper.java b/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapper.java
index e818520..f3373a6 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapper.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapper.java
@@ -1,13 +1,9 @@
 package dev.pcvolkmer.onco.datamapper.mapper;
 
 import dev.pcvolkmer.mv64e.mtb.*;
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.datacatalogues.KpaCatalogue;
 
-import java.util.Map;
-
-import static dev.pcvolkmer.onco.datamapper.TypeMapper.asDate;
-import static dev.pcvolkmer.onco.datamapper.TypeMapper.asString;
-
 /**
  * Mapper class to load and map patient data from database table 'dk_dnpm_kpa'
  *
@@ -34,18 +30,18 @@ public class KpaPatientDataMapper implements DataMapper<Patient> {
 
         var builder = Patient.builder();
         builder
-                .id(asString(kpaData.get("patient_id")))
+                .id(kpaData.getString("patient_id"))
                 .gender(getGenderCoding(kpaData))
-                .birthDate(mapDate(asDate(kpaData.get("geburtsdatum"))))
-                .dateOfDeath(mapDate(asDate(kpaData.get("todesdatum"))))
+                .birthDate(mapDate(kpaData.getDate("geburtsdatum")))
+                .dateOfDeath(mapDate(kpaData.getDate("todesdatum")))
                 .healthInsurance(getHealthInsurance(kpaData))
         ;
         return builder.build();
     }
 
-    private GenderCoding getGenderCoding(Map<String, Object> data) {
+    private GenderCoding getGenderCoding(ResultSet data) {
         var genderCodingBuilder = GenderCoding.builder();
-        String geschlecht = asString(data.get("geschlecht"));
+        String geschlecht = data.getString("geschlecht");
         switch (geschlecht) {
             case "m":
                 genderCodingBuilder.code(GenderCodingCode.MALE);
@@ -63,9 +59,9 @@ public class KpaPatientDataMapper implements DataMapper<Patient> {
         return genderCodingBuilder.build();
     }
 
-    private HealthInsurance getHealthInsurance(Map<String, Object> data) {
+    private HealthInsurance getHealthInsurance(ResultSet data) {
         var healthInsuranceCodingBuilder = HealthInsuranceCoding.builder();
-        String healthInsuranceType = asString(data.get("artderkrankenkasse"));
+        String healthInsuranceType = data.getString("artderkrankenkasse");
         if (healthInsuranceType == null) {
             healthInsuranceCodingBuilder.code(HealthInsuranceCodingCode.UNK).build();
             return HealthInsurance.builder().type(healthInsuranceCodingBuilder.build()).build();
diff --git a/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapper.java b/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapper.java
index 557e3c1..a7e01b3 100644
--- a/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapper.java
+++ b/src/main/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapper.java
@@ -4,14 +4,10 @@ import dev.pcvolkmer.mv64e.mtb.Address;
 import dev.pcvolkmer.mv64e.mtb.GenderCoding;
 import dev.pcvolkmer.mv64e.mtb.GenderCodingCode;
 import dev.pcvolkmer.mv64e.mtb.Patient;
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.datacatalogues.PatientCatalogue;
 import dev.pcvolkmer.onco.datamapper.exceptions.DataAccessException;
 
-import java.util.Map;
-
-import static dev.pcvolkmer.onco.datamapper.TypeMapper.asDate;
-import static dev.pcvolkmer.onco.datamapper.TypeMapper.asString;
-
 /**
  * Mapper class to load and map diagnosis data from database table 'dk_dnpm_kpa'
  *
@@ -33,23 +29,23 @@ public class PatientDataMapper implements DataMapper<Patient> {
      * @return The loaded MtbDiagnosis file
      */
     @Override
-    public Patient getById(int id) {
+    public Patient getById(final int id) {
         var patientData = patientCatalogue.getById(id);
 
         var builder = Patient.builder();
         builder
-                .id(asString(patientData.get("id")))
+                .id(patientData.getString("id"))
                 .gender(getGenderCoding(patientData))
-                .birthDate(mapDate(asDate(patientData.get("geburtsdatum"))))
-                .dateOfDeath(mapDate(asDate(patientData.get("sterbedatum"))))
+                .birthDate(mapDate(patientData.getDate("geburtsdatum")))
+                .dateOfDeath(mapDate(patientData.getDate("sterbedatum")))
                 .address(Address.builder().municipalityCode(getMunicipalityCode(patientData)).build())
         ;
         return builder.build();
     }
 
-    private GenderCoding getGenderCoding(Map<String, Object> data) {
+    private GenderCoding getGenderCoding(final ResultSet data) {
         var genderCodingBuilder = GenderCoding.builder();
-        String geschlecht = asString(data.get("geschlecht"));
+        String geschlecht = data.getString("geschlecht");
         switch (geschlecht) {
             case "M":
                 genderCodingBuilder.code(GenderCodingCode.MALE);
@@ -66,8 +62,8 @@ public class PatientDataMapper implements DataMapper<Patient> {
         return genderCodingBuilder.build();
     }
 
-    private String getMunicipalityCode(Map<String, Object> data) {
-        var gkz = asString(data.get("GKZ"));
+    private String getMunicipalityCode(final ResultSet data) {
+        var gkz = data.getString("GKZ");
         if (gkz == null || gkz.trim().length() != 8) {
             throw new DataAccessException("Municipality code not found");
         }
diff --git a/src/test/java/dev/pcvolkmer/onco/datamapper/ResultSetTest.java b/src/test/java/dev/pcvolkmer/onco/datamapper/ResultSetTest.java
new file mode 100644
index 0000000..f8c0deb
--- /dev/null
+++ b/src/test/java/dev/pcvolkmer/onco/datamapper/ResultSetTest.java
@@ -0,0 +1,46 @@
+package dev.pcvolkmer.onco.datamapper;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+import java.sql.Date;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ResultSetTest {
+
+    @Test
+    void shouldReturnStringValues() {
+        var data = getTestData();
+
+        assertThat(data.getString("null")).isNull();
+        assertThat(data.getString("string")).isEqualTo("TestString");
+        assertThat(data.getString("int")).isEqualTo("42");
+    }
+
+    @Test
+    void shouldReturnIntegerValues() {
+        var data = getTestData();
+
+        assertThat(data.getInteger("int")).isEqualTo(42);
+    }
+
+    @Test
+    void shouldReturnDateValues() {
+        var data = getTestData();
+
+        assertThat(data.getDate("date")).isEqualTo(new Date(Date.from(Instant.parse("2025-06-21T12:00:00Z")).getTime()));
+    }
+
+    static ResultSet getTestData() {
+        return ResultSet.from(
+                Map.of(
+                        "string", "TestString",
+                        "int", 42,
+                        "date", new Date(Date.from(Instant.parse("2025-06-21T12:00:00Z")).getTime())
+                )
+        );
+    }
+
+}
diff --git a/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapperTest.java b/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapperTest.java
index 1cae4d5..5b6f5c6 100644
--- a/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapperTest.java
+++ b/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaDiagnosisDataMapperTest.java
@@ -1,6 +1,7 @@
 package dev.pcvolkmer.onco.datamapper.mapper;
 
 import dev.pcvolkmer.mv64e.mtb.MtbDiagnosis;
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.datacatalogues.KpaCatalogue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -35,11 +36,11 @@ class KpaDiagnosisDataMapperTest {
     }
 
     @Test
-    void shouldCreateDiagnosis(@Mock Map<String, Object> resultSet) {
+    void shouldCreateDiagnosis(@Mock ResultSet resultSet) {
         doAnswer(invocationOnMock -> {
             var columnName = invocationOnMock.getArgument(0, String.class);
             return testData().get(columnName);
-        }).when(resultSet).get(anyString());
+        }).when(resultSet).getString(anyString());
 
         doAnswer(invocationOnMock -> resultSet)
                 .when(kpaCatalogue)
diff --git a/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapperTest.java b/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapperTest.java
index a18129f..e0edd30 100644
--- a/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapperTest.java
+++ b/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/KpaPatientDataMapperTest.java
@@ -1,6 +1,7 @@
 package dev.pcvolkmer.onco.datamapper.mapper;
 
 import dev.pcvolkmer.mv64e.mtb.*;
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.datacatalogues.KpaCatalogue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -37,7 +38,7 @@ class KpaPatientDataMapperTest {
     }
 
     @Test
-    void shouldCreatePatientAlive(@Mock Map<String, Object> resultSet) {
+    void shouldCreatePatientAlive(@Mock ResultSet resultSet) {
         var testData = Map.of(
                 "patient_id", "1",
                 "geschlecht", "m",
@@ -49,7 +50,12 @@ class KpaPatientDataMapperTest {
         doAnswer(invocationOnMock -> {
             var columnName = invocationOnMock.getArgument(0, String.class);
             return testData.get(columnName);
-        }).when(resultSet).get(anyString());
+        }).when(resultSet).getString(anyString());
+
+        doAnswer(invocationOnMock -> {
+            var columnName = invocationOnMock.getArgument(0, String.class);
+            return testData.get(columnName);
+        }).when(resultSet).getDate(anyString());
 
         doAnswer(invocationOnMock -> resultSet)
                 .when(kpaCatalogue)
@@ -67,7 +73,7 @@ class KpaPatientDataMapperTest {
     }
 
     @Test
-    void shouldCreatePatientDead(@Mock Map<String, Object> resultSet) {
+    void shouldCreatePatientDead(@Mock ResultSet resultSet) {
         var testData = Map.of(
                 "patient_id", "1",
                 "geschlecht", "w",
@@ -78,7 +84,12 @@ class KpaPatientDataMapperTest {
         doAnswer(invocationOnMock -> {
             var columnName = invocationOnMock.getArgument(0, String.class);
             return testData.get(columnName);
-        }).when(resultSet).get(anyString());
+        }).when(resultSet).getString(anyString());
+
+        doAnswer(invocationOnMock -> {
+            var columnName = invocationOnMock.getArgument(0, String.class);
+            return testData.get(columnName);
+        }).when(resultSet).getDate(anyString());
 
         doAnswer(invocationOnMock -> resultSet)
                 .when(kpaCatalogue)
diff --git a/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapperTest.java b/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapperTest.java
index 9792cd2..b1a4869 100644
--- a/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapperTest.java
+++ b/src/test/java/dev/pcvolkmer/onco/datamapper/mapper/PatientDataMapperTest.java
@@ -3,6 +3,7 @@ package dev.pcvolkmer.onco.datamapper.mapper;
 import dev.pcvolkmer.mv64e.mtb.Address;
 import dev.pcvolkmer.mv64e.mtb.GenderCodingCode;
 import dev.pcvolkmer.mv64e.mtb.Patient;
+import dev.pcvolkmer.onco.datamapper.ResultSet;
 import dev.pcvolkmer.onco.datamapper.datacatalogues.PatientCatalogue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -39,7 +40,7 @@ class PatientDataMapperTest {
     }
 
     @Test
-    void shouldCreatePatientAlive(@Mock Map<String, Object> resultSet) {
+    void shouldCreatePatientAlive(@Mock ResultSet resultSet) {
         var testData = Map.of(
                 "id", "1",
                 "geschlecht", "M",
@@ -51,7 +52,12 @@ class PatientDataMapperTest {
         doAnswer(invocationOnMock -> {
             var columnName = invocationOnMock.getArgument(0, String.class);
             return testData.get(columnName);
-        }).when(resultSet).get(anyString());
+        }).when(resultSet).getString(anyString());
+
+        doAnswer(invocationOnMock -> {
+            var columnName = invocationOnMock.getArgument(0, String.class);
+            return testData.get(columnName);
+        }).when(resultSet).getDate(anyString());
 
         doAnswer(invocationOnMock -> resultSet)
                 .when(patientCatalogue)
@@ -67,7 +73,7 @@ class PatientDataMapperTest {
     }
 
     @Test
-    void shouldCreatePatientDead(@Mock Map<String, Object> resultSet) {
+    void shouldCreatePatientDead(@Mock ResultSet resultSet) {
         var testData = Map.of(
                 "id", "1",
                 "geschlecht", "M",
@@ -78,7 +84,12 @@ class PatientDataMapperTest {
         doAnswer(invocationOnMock -> {
             var columnName = invocationOnMock.getArgument(0, String.class);
             return testData.get(columnName);
-        }).when(resultSet).get(anyString());
+        }).when(resultSet).getString(anyString());
+
+        doAnswer(invocationOnMock -> {
+            var columnName = invocationOnMock.getArgument(0, String.class);
+            return testData.get(columnName);
+        }).when(resultSet).getDate(anyString());
 
         doAnswer(invocationOnMock -> resultSet)
                 .when(patientCatalogue)