diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/Endpoint.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/Endpoint.java
index 2ad4a0fd..d1b31085 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/Endpoint.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/Endpoint.java
@@ -16,7 +16,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class Endpoint implements Model {
+public final class Endpoint implements Model, HasId {
   @JsonProperty
   private long id;
 
@@ -49,10 +49,11 @@ public final class Endpoint implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    return queryParams.containsKey("id") && queryParams.get("id").equals(this.id);
+    return QueryParamsComparator.isIdEqual(this, queryParams);
   }
+
 }
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/Engagement.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/Engagement.java
index 25f1c6a3..16a7d80a 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/Engagement.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/Engagement.java
@@ -17,12 +17,12 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class Engagement implements Model {
+public final class Engagement implements Model, HasId, HasName {
   @JsonProperty("branch_tag")
   private String branch;
 
   @JsonProperty
-  private Long id;
+  private long id;
 
   @JsonProperty
   private String name;
@@ -94,15 +94,15 @@ public final class Engagement implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id") != null && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name") != null && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/Finding.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/Finding.java
index 426fe6e2..1e3677eb 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/Finding.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/Finding.java
@@ -21,7 +21,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class Finding implements Model {
+public final class Finding implements Model, HasId {
   @JsonProperty
   private long id;
 
@@ -121,11 +121,11 @@ public String getNumericalSeverity() {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    return queryParams.containsKey("id") && queryParams.get("id").equals(this.id);
+    return QueryParamsComparator.isIdEqual(this, queryParams);
   }
 
   public enum Severity {
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/Group.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/Group.java
index 7f96bd15..3d7e0f5c 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/Group.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/Group.java
@@ -17,7 +17,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class Group implements Model {
+public final class Group implements Model, HasId, HasName {
   @JsonProperty
   private long id;
 
@@ -36,15 +36,15 @@ public final class Group implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/HasId.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/HasId.java
new file mode 100644
index 00000000..8c8e1092
--- /dev/null
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/HasId.java
@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: the secureCodeBox authors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package io.securecodebox.persistence.defectdojo.model;
+
+/**
+ * Interface to mark {@link Model models} which have an id
+ * <p>
+ * This type is package private because it is an implementation detail of the models and
+ * z should not be used outside of this package.
+ * </p>
+ */
+interface HasId {
+  long getId();
+
+  void setId(long id);
+}
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/HasName.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/HasName.java
new file mode 100644
index 00000000..6d5b9a3a
--- /dev/null
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/HasName.java
@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: the secureCodeBox authors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package io.securecodebox.persistence.defectdojo.model;
+
+/**
+ * Interface to mark {@link Model models} which have a name
+ * <p>
+ * This type is package private because it is an implementation detail of the models and
+ * z should not be used outside of this package.
+ * </p>
+ */
+interface HasName {
+  String getName();
+
+  void setName(String id);
+}
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/Product.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/Product.java
index 2f703153..f5cb2824 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/Product.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/Product.java
@@ -17,7 +17,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class Product implements Model {
+public final class Product implements Model, HasId, HasName {
   @JsonProperty
   private long id;
 
@@ -53,15 +53,15 @@ public final class Product implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/ProductType.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/ProductType.java
index 38fbb893..6aac466e 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/ProductType.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/ProductType.java
@@ -16,7 +16,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class ProductType implements Model {
+public final class ProductType implements Model, HasId, HasName {
   @JsonProperty
   private long id;
 
@@ -32,15 +32,15 @@ public final class ProductType implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/QueryParamsComparator.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/QueryParamsComparator.java
new file mode 100644
index 00000000..bcc30c6b
--- /dev/null
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/QueryParamsComparator.java
@@ -0,0 +1,65 @@
+// SPDX-FileCopyrightText: the secureCodeBox authors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package io.securecodebox.persistence.defectdojo.model;
+
+import java.util.Map;
+
+/**
+ * Pure static helper class
+ * <p>
+ * This type is package private because it is an implementation detail of the models and
+ * should not be used outside of this package.
+ * </p>
+ */
+final class QueryParamsComparator {
+
+  static final String QUERY_PARAM_KEY_FOR_ID = "id";
+  static final String QUERY_PARAM_KEY_FOR_NAME = "name";
+
+  private QueryParamsComparator() {
+    super();
+  }
+
+  static boolean isNull(Object o) {
+    return o == null;
+  }
+
+  static boolean isIdEqual(HasId model, Map<String, Object> queryParams) {
+    if (isNull(model)) {
+      return false;
+    }
+
+    if (isNull(queryParams)) {
+      return false;
+    }
+
+    if (!queryParams.containsKey(QUERY_PARAM_KEY_FOR_ID)) {
+      return false;
+    }
+
+    // FIXME: Since th generic type for value is Object, possible NPE here!
+    return queryParams.get(QUERY_PARAM_KEY_FOR_ID).equals(model.getId());
+  }
+
+  static boolean isNameEqual(HasName model, Map<String, Object> queryParams) {
+    if (isNull(model)) {
+      return false;
+    }
+
+    if (isNull(queryParams)) {
+      return false;
+    }
+
+    if (!queryParams.containsKey(QUERY_PARAM_KEY_FOR_NAME)) {
+      return false;
+    }
+
+    if (isNull(queryParams.get(QUERY_PARAM_KEY_FOR_NAME))) {
+      return false;
+    }
+
+    return queryParams.get(QUERY_PARAM_KEY_FOR_NAME).equals(model.getName());
+  }
+}
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/RiskAcceptance.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/RiskAcceptance.java
index 2fa127fc..fe6bc08f 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/RiskAcceptance.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/RiskAcceptance.java
@@ -17,7 +17,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class RiskAcceptance implements Model {
+public final class RiskAcceptance implements Model, HasId {
   @JsonProperty
   private long id;
 
@@ -58,10 +58,10 @@ public final class RiskAcceptance implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    return queryParams.containsKey("id") && queryParams.get("id").equals(this.id);
+    return QueryParamsComparator.isIdEqual(this, queryParams);
   }
 }
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/Test.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/Test.java
index adb6a5cd..4b378fba 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/Test.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/Test.java
@@ -18,7 +18,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class Test implements Model {
+public final class Test implements Model, HasId {
   @JsonProperty
   private long id;
 
@@ -63,11 +63,11 @@ public final class Test implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/TestType.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/TestType.java
index 28864aee..a1cff33a 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/TestType.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/TestType.java
@@ -16,7 +16,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class TestType implements Model {
+public final class TestType implements Model, HasId, HasName {
   @JsonProperty
   private long id;
 
@@ -33,15 +33,15 @@ public final class TestType implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolConfig.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolConfig.java
index 60917d60..9992ae36 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolConfig.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolConfig.java
@@ -16,7 +16,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class ToolConfig implements Model {
+public final class ToolConfig implements Model, HasId, HasName {
   @JsonProperty
   private long id;
 
@@ -38,15 +38,15 @@ public final class ToolConfig implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolType.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolType.java
index ed1a008b..e4e14213 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolType.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/ToolType.java
@@ -16,7 +16,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class ToolType implements Model {
+public final class ToolType implements Model, HasId, HasName {
   @JsonProperty
   private long id;
 
@@ -29,15 +29,15 @@ public final class ToolType implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
-    if (queryParams.containsKey("name") && queryParams.get("name").equals(this.name)) {
+    if (QueryParamsComparator.isNameEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/main/java/io/securecodebox/persistence/defectdojo/model/User.java b/src/main/java/io/securecodebox/persistence/defectdojo/model/User.java
index fecb30f1..737be18d 100644
--- a/src/main/java/io/securecodebox/persistence/defectdojo/model/User.java
+++ b/src/main/java/io/securecodebox/persistence/defectdojo/model/User.java
@@ -16,7 +16,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public final class User implements Model {
+public final class User implements Model, HasId {
   @JsonProperty
   private long id;
 
@@ -32,11 +32,11 @@ public final class User implements Model {
 
   @Override
   public boolean equalsQueryString(Map<String, Object> queryParams) {
-    if (queryParams == null) {
+    if (QueryParamsComparator.isNull(queryParams)) {
       return false;
     }
 
-    if (queryParams.containsKey("id") && queryParams.get("id").equals(this.id)) {
+    if (QueryParamsComparator.isIdEqual(this, queryParams)) {
       return true;
     }
 
diff --git a/src/test/java/io/securecodebox/persistence/defectdojo/model/QueryParamsComparatorTest.java b/src/test/java/io/securecodebox/persistence/defectdojo/model/QueryParamsComparatorTest.java
new file mode 100644
index 00000000..956e9e07
--- /dev/null
+++ b/src/test/java/io/securecodebox/persistence/defectdojo/model/QueryParamsComparatorTest.java
@@ -0,0 +1,145 @@
+// SPDX-FileCopyrightText: the secureCodeBox authors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package io.securecodebox.persistence.defectdojo.model;
+
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+import java.util.HashMap;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests for {@link QueryParamsComparator}
+ */
+class QueryParamsComparatorTest {
+  @Test
+  void isNull() {
+    assertAll(
+      () -> assertThat(QueryParamsComparator.isNull(null), is(true)),
+      () -> assertThat(QueryParamsComparator.isNull(Collections.emptyMap()), is(false))
+    );
+  }
+
+  @Test
+  void isIdEqual_falseIfModelIsNull() {
+    assertThat(
+      QueryParamsComparator.isIdEqual(null, Collections.emptyMap()),
+      is(false));
+  }
+
+  @Test
+  void isIdEqual_falseIfQueryParamsIsNull() {
+    assertThat(
+      QueryParamsComparator.isIdEqual(mock(HasId.class), null),
+      is(false));
+  }
+
+  @Test
+  void isIdEqual_falseIfQueryParamsDoesNotContainId() {
+    assertThat(
+      QueryParamsComparator.isIdEqual(mock(HasId.class), Collections.emptyMap()),
+      is(false));
+  }
+
+  @Test
+  @Disabled("Unclear if this behaviour will break something.")
+  void isIdEqual_falseIfQueryParamValueIsNull() {
+    final var queryParams = new HashMap<String, Object>();
+    queryParams.put(QueryParamsComparator.QUERY_PARAM_KEY_FOR_ID, null);
+
+    assertThat(
+      QueryParamsComparator.isIdEqual(mock(HasId.class), queryParams),
+      is(false));
+  }
+
+  @Test
+  void isIdEqual_trueForSameNumbers() {
+    final var model = mock(HasId.class);
+    when(model.getId()).thenReturn(42L);
+
+    final var queryParams = new HashMap<String, Object>();
+    queryParams.put(QueryParamsComparator.QUERY_PARAM_KEY_FOR_ID, 42L);
+
+    assertThat(
+      QueryParamsComparator.isIdEqual(model, queryParams),
+      is(true));
+  }
+
+  @Test
+  void isIdEqual_falseForDifferentNumbers() {
+    final var model = mock(HasId.class);
+    when(model.getId()).thenReturn(42L);
+
+    final var queryParams = new HashMap<String, Object>();
+    queryParams.put(QueryParamsComparator.QUERY_PARAM_KEY_FOR_ID, 23L);
+
+    assertThat(
+      QueryParamsComparator.isIdEqual(mock(HasId.class), queryParams),
+      is(false));
+  }
+
+  @Test
+  void isNameEqual_falseIfModelIsNull() {
+    assertThat(
+      QueryParamsComparator.isNameEqual(null, Collections.emptyMap()),
+      is(false));
+  }
+
+  @Test
+  void isNameEqual_falseIfQueryParamsIsNull() {
+    assertThat(
+      QueryParamsComparator.isNameEqual(mock(HasName.class), null),
+      is(false));
+  }
+
+  @Test
+  void isNameEqual_falseIfQueryParamsDoesNotContainId() {
+    assertThat(
+      QueryParamsComparator.isNameEqual(mock(HasName.class), Collections.emptyMap()),
+      is(false));
+  }
+
+  @Test
+  void isNameEqual_falseIfQueryParamValueIsNull() {
+    final var queryParams = new HashMap<String, Object>();
+    queryParams.put(QueryParamsComparator.QUERY_PARAM_KEY_FOR_NAME, null);
+
+    assertThat(
+      QueryParamsComparator.isNameEqual(mock(HasName.class), queryParams),
+      is(false));
+  }
+
+  @Test
+  void isNameEqual_trueForSameValues() {
+    final var model = mock(HasName.class);
+    when(model.getName()).thenReturn("foobar");
+
+    final var queryParams = new HashMap<String, Object>();
+    queryParams.put(QueryParamsComparator.QUERY_PARAM_KEY_FOR_NAME, "foobar");
+
+    assertThat(
+      QueryParamsComparator.isNameEqual(model, queryParams),
+      is(true));
+  }
+
+  @Test
+  void isNameEqual_falseForDifferentValues() {
+    final var model = mock(HasName.class);
+    when(model.getName()).thenReturn("foobar");
+
+    final var queryParams = new HashMap<String, Object>();
+    queryParams.put(QueryParamsComparator.QUERY_PARAM_KEY_FOR_NAME, "snafu");
+
+    assertThat(
+      QueryParamsComparator.isNameEqual(model, queryParams),
+      is(false));
+  }
+}