diff --git a/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DataRepositoryTests.java b/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DataRepositoryTests.java
new file mode 100644
index 0000000..3a8fa41
--- /dev/null
+++ b/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DataRepositoryTests.java
@@ -0,0 +1,80 @@
+package de.uni_passau.fim.PADAS.group3.DataDash.Dataset;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DataJpaTest
+public class DataRepositoryTests {
+
+    @Autowired
+    private dataRepository dataRepository;
+    
+    @BeforeEach
+    private void clearDatabase() {
+        dataRepository.deleteAll();
+    }
+
+    @Test
+    public void testFindByOptionalCriteria() {
+        // Prepare test data
+        Dataset dataset = new Dataset("title", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset);
+
+        // Execute the method under test
+        Page<Dataset> result = dataRepository.findByOptionalCriteria(
+                Optional.of("title"), Optional.empty(), Optional.empty(), Optional.empty(),
+                Optional.empty(), Optional.empty(), Optional.empty(), PageRequest.of(0, 10));
+
+        // Assertions
+        assertThat(result.getContent()).hasSize(1);
+        assertThat(result.getContent().get(0).getTitle()).isEqualTo("title");
+    }
+    @Test
+    public void searchByOptionalCriteria() {
+        Dataset dataset1 = new Dataset("water", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset1);
+        Dataset dataset = new Dataset("title1", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset);
+        dataset = new Dataset("title1", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset);
+         
+        Page<Dataset> result = dataRepository.searchByOptionalCriteria(
+                Optional.of("water"), Optional.empty(), PageRequest.of(0, 10));
+
+            assertThat(result.getContent()).hasSize(1);
+            assertThat(result.getContent().get(0).getTitle()).isEqualTo("water");
+    }
+    @Test
+    public void searchByOptionalCriteriaMulti() {
+        Dataset dataset1 = new Dataset("title", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset1);
+        Dataset dataset = new Dataset("title1", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset);
+        dataset = new Dataset("title1", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataRepository.save(dataset);
+         
+        Page<Dataset> result = dataRepository.searchByOptionalCriteria(
+                Optional.of("title%"), Optional.empty(), PageRequest.of(0, 10));
+
+            assertThat(result.getContent()).hasSize(3);
+    }
+
+    @Test
+    public void getDatasetById() {
+        Dataset dataset = new Dataset("title", "abst", "desc", "auth", null, null, Type.API, "MIT");
+        dataset = dataRepository.save(dataset);
+
+        Dataset result = dataRepository.getDatasetById(dataset.getId());
+
+        assertThat(result).isNotNull();
+        assertThat(result.getTitle()).isEqualTo("title");
+    }   
+}
\ No newline at end of file
diff --git a/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DatasetControllerTests.java b/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DatasetControllerTests.java
index 634287a..8a3c7d9 100644
--- a/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DatasetControllerTests.java
+++ b/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/Dataset/DatasetControllerTests.java
@@ -45,9 +45,7 @@ public class DatasetControllerTests {
     @Test
     void getDatasetById_whenExists() throws Exception {
         UUID id = UUID.randomUUID();
-        Dataset dataset = new Dataset("Title", "abst", "desc", "auth", null, null, Type.API, "MIT"); // Assuming a
-                                                                                                     // constructor or
-                                                                                                     // builder pattern
+        Dataset dataset = new Dataset("Title", "abst", "desc", "auth", null, null, Type.API, "MIT");
         given(datasetService.getDatasetById(id)).willReturn(dataset);
 
         mockMvc.perform(get("/api/v1/datasets/id/" + id.toString()))
@@ -233,68 +231,77 @@ public class DatasetControllerTests {
 
     @Test
     void searchDatasets_whenExists() throws Exception {
-        String keyword = "data";
+        String keyword = "title%";
         List<Dataset> datasets = Arrays.asList(
-                new Dataset("Title 1", "abst", "data", "auth", null, null, Type.API, "MIT"),
-                new Dataset("Title 2", "abst", "data", "auth", null, null, Type.API, "MIT"));
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(new PageImpl<>(datasets));
+                new Dataset("Title 1", "abst", "data", "auth", null, null, Type.API, "MIT"));
+        // new Dataset("Title 2", "abst", "data", "auth", null, null, Type.API, "MIT"));
 
-        mockMvc.perform(get("/api/v1/datasets/search?searach=" + keyword))
-                .andExpect(status().isOk());
-                //TODO: Check output
+        Page<Dataset> page = new PageImpl<>(datasets);
+        given(datasetService.searchByOptionalCriteria(keyword, "%", "%",
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(page);
+        String s = objectMapper.writeValueAsString(page);
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword))
+                .andExpect(status().isOk())
+                .andExpect(content().json(s));
     }
 
     @Test
     void searchDatasets_whenNotExists() throws Exception {
         String keyword = "nonexistent";
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(Page.empty());
+        given(datasetService.searchByOptionalCriteria(keyword, null, null,
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(Page.empty());
 
-        mockMvc.perform(get("/api/v1/datasets/search?seaarch=" + keyword))
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword))
                 .andExpect(status().isOk());
     }
 
     @Test
     void searchDatasets_whenInvalidSort() throws Exception {
         String keyword = "data";
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(Page.empty());
+        given(datasetService.searchByOptionalCriteria(keyword, null, null,
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(Page.empty());
 
-        mockMvc.perform(get("/api/v1/datasets/search?searach=" + keyword + "&sort=invalid"))
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword + "&sort=invalid"))
                 .andExpect(status().isBadRequest());
     }
 
     @Test
     void searchDatasets_whenInvalidDirection() throws Exception {
         String keyword = "data";
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(Page.empty());
+        given(datasetService.searchByOptionalCriteria(keyword, null, null,
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(Page.empty());
 
-        mockMvc.perform(get("/api/v1/datasets/search?searach=" + keyword + "&direction=invalid"))
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword + "&direction=invalid"))
                 .andExpect(status().isBadRequest());
     }
 
     @Test
     void searchDatasets_whenInvalidPage() throws Exception {
         String keyword = "data";
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(Page.empty());
+        given(datasetService.searchByOptionalCriteria(keyword, null, null,
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(Page.empty());
 
-        mockMvc.perform(get("/api/v1/datasets/search?searach=" + keyword + "&page=-1"))
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword + "&page=-1"))
                 .andExpect(status().isBadRequest());
     }
 
     @Test
     void searchDatasets_whenInvalidSize() throws Exception {
         String keyword = "data";
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(Page.empty());
+        given(datasetService.searchByOptionalCriteria(keyword, null, null,
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(Page.empty());
 
-        mockMvc.perform(get("/api/v1/datasets/search?searach=" + keyword + "&size=-1"))
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword + "&size=-1"))
                 .andExpect(status().isBadRequest());
     }
 
     @Test
     void searchDatasets_whenInvalidSize2() throws Exception {
         String keyword = "data";
-        given(datasetService.searchByOptionalCriteria(keyword,null,null,PageRequest.of(0,20,Sort.by(Sort.Direction.DESC,"upvotes")))).willReturn(Page.empty());
+        given(datasetService.searchByOptionalCriteria(keyword, null, null,
+                PageRequest.of(0, 20, Sort.by(Sort.Direction.DESC, "upvotes")))).willReturn(Page.empty());
 
-        mockMvc.perform(get("/api/v1/datasets/search?searach=" + keyword + "&size=0"))
+        mockMvc.perform(get("/api/v1/datasets/search?search=" + keyword + "&size=0"))
                 .andExpect(status().isBadRequest());
     }
 
diff --git a/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/category/CategoryRepositoryTests.java b/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/category/CategoryRepositoryTests.java
new file mode 100644
index 0000000..2330d6c
--- /dev/null
+++ b/src/test/java/de/uni_passau/fim/PADAS/group3/DataDash/category/CategoryRepositoryTests.java
@@ -0,0 +1,56 @@
+package de.uni_passau.fim.PADAS.group3.DataDash.category;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+
+import java.util.List;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DataJpaTest
+public class CategoryRepositoryTests {
+
+    @Autowired
+    private CategoryRepository categoryRepository;
+
+    private Category savedCategory;
+
+    @BeforeEach
+    public void setup() {
+        // Setup data for each test
+        Category category = new Category();
+        category.setName("Test Category");
+        // Assuming Category class has a setName method and an ID that is auto-generated
+        savedCategory = categoryRepository.save(category);
+    }
+
+    @Test
+    public void whenFindById_thenReturnCategory() {
+        Optional<Category> foundCategory = categoryRepository.findById(savedCategory.getId());
+        assertThat(foundCategory).isPresent();
+        assertThat(foundCategory.get().getId()).isEqualTo(savedCategory.getId());
+    }
+
+    @Test
+    public void whenFindByName_thenReturnCategoryList() {
+        List<Category> categories = categoryRepository.findByName("Test Category");
+        assertThat(categories).hasSize(1);
+        assertThat(categories.get(0).getName()).isEqualTo("Test Category");
+    }
+
+    @Test
+    public void whenFindAll_thenReturnAllCategories() {
+        List<Category> categories = categoryRepository.findAll();
+        assertThat(categories).isNotEmpty();
+    }
+
+    @Test
+    public void whenGetCategoryById_thenReturnCategory() {
+        Category foundCategory = categoryRepository.getCategoryById(savedCategory.getId());
+        assertThat(foundCategory).isNotNull();
+        assertThat(foundCategory.getId()).isEqualTo(savedCategory.getId());
+    }
+}
\ No newline at end of file