diff --git a/backend/.idea/workspace.xml b/backend/.idea/workspace.xml
index 1088a8b..f391dca 100644
--- a/backend/.idea/workspace.xml
+++ b/backend/.idea/workspace.xml
@@ -4,11 +4,8 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="3a869f59-290a-4ab2-b036-a878ce801bc4" name="Changes" comment="Fix failing test case">
-      <change afterPath="$PROJECT_DIR$/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/src/test/resources/taskgroupRepositoryTestEntries.sql" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/core/entities/timemanager/Taskgroup.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/core/entities/timemanager/Taskgroup.java" afterDir="false" />
+    <list default="true" id="3a869f59-290a-4ab2-b036-a878ce801bc4" name="Changes" comment="TaskgroupRepsitoryTest">
+      <change beforePath="$PROJECT_DIR$/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -87,7 +84,7 @@
       <recent name="$PROJECT_DIR$/src/test/java/core/taskgroups" />
     </key>
   </component>
-  <component name="RunManager" selected="JUnit.TaskgroupRepsitoryTest">
+  <component name="RunManager" selected="JUnit.TaskgroupRepsitoryTest.delete">
     <configuration name="TaskgroupRepsitoryTest" type="JUnit" factoryName="JUnit" temporary="true" nameIsGenerated="true">
       <module name="demo" />
       <extension name="coverage">
@@ -103,6 +100,22 @@
         <option name="Make" enabled="true" />
       </method>
     </configuration>
+    <configuration name="TaskgroupRepsitoryTest.delete" type="JUnit" factoryName="JUnit" temporary="true" nameIsGenerated="true">
+      <module name="demo" />
+      <extension name="coverage">
+        <pattern>
+          <option name="PATTERN" value="core.taskgroups.*" />
+          <option name="ENABLED" value="true" />
+        </pattern>
+      </extension>
+      <option name="PACKAGE_NAME" value="core.taskgroups" />
+      <option name="MAIN_CLASS_NAME" value="core.taskgroups.TaskgroupRepsitoryTest" />
+      <option name="METHOD_NAME" value="delete" />
+      <option name="TEST_OBJECT" value="method" />
+      <method v="2">
+        <option name="Make" enabled="true" />
+      </method>
+    </configuration>
     <configuration name="TaskgroupRepsitoryTest.deleteAllByUser" type="JUnit" factoryName="JUnit" temporary="true" nameIsGenerated="true">
       <module name="demo" />
       <extension name="coverage">
@@ -135,22 +148,6 @@
         <option name="Make" enabled="true" />
       </method>
     </configuration>
-    <configuration name="TaskgroupRepsitoryTest.findAllByUser" type="JUnit" factoryName="JUnit" temporary="true" nameIsGenerated="true">
-      <module name="demo" />
-      <extension name="coverage">
-        <pattern>
-          <option name="PATTERN" value="core.taskgroups.*" />
-          <option name="ENABLED" value="true" />
-        </pattern>
-      </extension>
-      <option name="PACKAGE_NAME" value="core.taskgroups" />
-      <option name="MAIN_CLASS_NAME" value="core.taskgroups.TaskgroupRepsitoryTest" />
-      <option name="METHOD_NAME" value="findAllByUser" />
-      <option name="TEST_OBJECT" value="method" />
-      <method v="2">
-        <option name="Make" enabled="true" />
-      </method>
-    </configuration>
     <configuration name="TaskgroupRepsitoryTest.findAllTopTaskgroupsByUser" type="JUnit" factoryName="JUnit" temporary="true" nameIsGenerated="true">
       <module name="demo" />
       <extension name="coverage">
@@ -176,11 +173,11 @@
     </configuration>
     <recent_temporary>
       <list>
+        <item itemvalue="JUnit.TaskgroupRepsitoryTest.delete" />
         <item itemvalue="JUnit.TaskgroupRepsitoryTest" />
         <item itemvalue="JUnit.TaskgroupRepsitoryTest.deleteAllByUser" />
         <item itemvalue="JUnit.TaskgroupRepsitoryTest.findAllTopTaskgroupsByUser" />
         <item itemvalue="JUnit.TaskgroupRepsitoryTest.existsByTaskgroupNameAndUser" />
-        <item itemvalue="JUnit.TaskgroupRepsitoryTest.findAllByUser" />
       </list>
     </recent_temporary>
   </component>
@@ -215,7 +212,7 @@
       <workItem from="1699205483652" duration="3298000" />
       <workItem from="1699380499473" duration="2708000" />
       <workItem from="1699460935890" duration="5000" />
-      <workItem from="1699466564154" duration="3193000" />
+      <workItem from="1699466564154" duration="4487000" />
     </task>
     <task id="LOCAL-00001" summary="Structure Taskgroups in Hierarchies">
       <option name="closed" value="true" />
@@ -401,7 +398,15 @@
       <option name="project" value="LOCAL" />
       <updated>1699380549911</updated>
     </task>
-    <option name="localTasksCounter" value="24" />
+    <task id="LOCAL-00024" summary="TaskgroupRepsitoryTest">
+      <option name="closed" value="true" />
+      <created>1699470020407</created>
+      <option name="number" value="00024" />
+      <option name="presentableId" value="LOCAL-00024" />
+      <option name="project" value="LOCAL" />
+      <updated>1699470020407</updated>
+    </task>
+    <option name="localTasksCounter" value="25" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">
@@ -432,7 +437,8 @@
     <MESSAGE value="Write simple Testcase for ci/cd" />
     <MESSAGE value="Deactivate Overall System test (temporarly)" />
     <MESSAGE value="Fix failing test case" />
-    <option name="LAST_COMMIT_MESSAGE" value="Fix failing test case" />
+    <MESSAGE value="TaskgroupRepsitoryTest" />
+    <option name="LAST_COMMIT_MESSAGE" value="TaskgroupRepsitoryTest" />
   </component>
   <component name="XDebuggerManager">
     <breakpoint-manager>
diff --git a/backend/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java b/backend/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java
index 7e81bb7..3da0877 100644
--- a/backend/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java
+++ b/backend/src/test/java/core/taskgroups/TaskgroupRepsitoryTest.java
@@ -1,6 +1,7 @@
 package core.taskgroups;
 
 import core.entities.User;
+import core.entities.timemanager.Task;
 import core.entities.timemanager.Taskgroup;
 import core.repositories.timemanager.TaskgroupRepository;
 import org.junit.jupiter.api.Test;
@@ -90,4 +91,23 @@ public class TaskgroupRepsitoryTest {
             assertThat(testEntityManager.find(Taskgroup.class, i)).isNull();
         }
     }
+
+    @Test
+    @Sql("classpath:taskgroupRepositoryTestEntries.sql")
+    void delete() {
+        Taskgroup no_children = testEntityManager.find(Taskgroup.class, 1L);
+        Taskgroup taskgroup_with_children = testEntityManager.find(Taskgroup.class, 5L);
+
+        taskgroupRepository.delete(no_children);
+        assertThat(testEntityManager.find(Taskgroup.class, 1L)).isNull();
+        for(long i=2; i<=8; i++) {
+            assertThat(testEntityManager.find(Taskgroup.class, i)).isNotNull();
+        }
+
+        taskgroupRepository.delete(taskgroup_with_children);
+        for(long i=5; i<=8; i++) {
+            assertThat(testEntityManager.find(Taskgroup.class, i)).isNull();
+        }
+
+    }
 }