diff --git a/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/Table.java b/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/Table.java
index 3dd66a573cb2f4b4b21acd21d868038e5b7ee07f..c19555325c5f5baa2564deb10b048aba0f33b9d7 100644
--- a/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/Table.java
+++ b/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/Table.java
@@ -63,11 +63,11 @@ public class Table {
 
     @org.springframework.data.annotation.Transient
     @ToString.Exclude
-    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.DETACH)
+    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
     @JoinColumn(name = "tdbid", insertable = false, updatable = false)
     private Database database;
 
-    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.DETACH, mappedBy = "table")
+    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.MERGE, mappedBy = "table")
     @OrderBy("ordinalPosition")
     private List<TableColumn> columns;
 
diff --git a/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/columns/TableColumn.java b/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/columns/TableColumn.java
index 8ea2472b4bf0c5cd82bcdd21d4129515a38a1d8c..18412a2792a1f9f9a37c560a77fc00015de5b437 100644
--- a/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/columns/TableColumn.java
+++ b/fda-metadata-db/entities/src/main/java/at/tuwien/entities/database/table/columns/TableColumn.java
@@ -52,13 +52,13 @@ public class TableColumn implements Comparable<TableColumn> {
     private Long dfid;
 
     @ToString.Exclude
-    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.DETACH)
+    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
     @JoinColumn(name = "dfid", referencedColumnName = "id", insertable = false, updatable = false)
     private ContainerImageDate dateFormat;
 
     @org.springframework.data.annotation.Transient
     @ToString.Exclude
-    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.DETACH)
+    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
     @JoinColumns({
             @JoinColumn(name = "tid", referencedColumnName = "id", insertable = false, updatable = false),
             @JoinColumn(name = "cdbid", referencedColumnName = "tdbid", insertable = false, updatable = false)
@@ -117,7 +117,7 @@ public class TableColumn implements Comparable<TableColumn> {
     @CreatedDate
     private Instant created;
 
-    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.DETACH)
+    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
     @JoinTable(name = "mdb_columns_concepts",
             joinColumns = {
                     @JoinColumn(name = "cid", referencedColumnName = "id", insertable = false, updatable = false),
diff --git a/fda-query-service/rest-service/src/test/java/at/tuwien/service/QueryServiceIntegrationTest.java b/fda-query-service/rest-service/src/test/java/at/tuwien/service/QueryServiceIntegrationTest.java
index 455cc6a4bce926ea5bea3fb7b12ae31c0c768f04..a25a26c57a1c39b8b1a0706861fa74e9cf81bec0 100644
--- a/fda-query-service/rest-service/src/test/java/at/tuwien/service/QueryServiceIntegrationTest.java
+++ b/fda-query-service/rest-service/src/test/java/at/tuwien/service/QueryServiceIntegrationTest.java
@@ -5,6 +5,7 @@ import at.tuwien.api.database.query.QueryResultDto;
 import at.tuwien.api.database.table.TableCsvDto;
 import at.tuwien.config.DockerConfig;
 import at.tuwien.config.ReadyConfig;
+import at.tuwien.entities.database.table.Table;
 import at.tuwien.exception.*;
 import at.tuwien.listener.impl.RabbitMqListenerImpl;
 import at.tuwien.repository.jpa.*;
@@ -74,6 +75,9 @@ public class QueryServiceIntegrationTest extends BaseUnitTest {
     @Autowired
     private TableRepository tableRepository;
 
+    @Autowired
+    private TableColumnRepository tableColumnRepository;
+
     @Autowired
     private ConceptRepository conceptRepository;
 
@@ -169,25 +173,31 @@ public class QueryServiceIntegrationTest extends BaseUnitTest {
         databaseRepository.save(DATABASE_1);
         databaseRepository.save(DATABASE_2);
         databaseRepository.save(DATABASE_3);
-        /* create tables */
+        /* create tables 1 */
         TABLE_1.setDatabase(DATABASE_1);
+        tableRepository.save(TABLE_1);
         TABLE_1.setColumns(TABLE_1_COLUMNS);
-        TABLE_1_COLUMNS.forEach(column -> column.setTable(TABLE_1));
         tableRepository.save(TABLE_1);
+        TABLE_1_COLUMNS.forEach(column -> column.setTable(TABLE_1));
+        /* create tables 2 */
         TABLE_2.setDatabase(DATABASE_1);
+        tableRepository.save(TABLE_2);
         TABLE_2.setColumns(TABLE_2_COLUMNS);
-        TABLE_2_COLUMNS.forEach(column -> column.setTable(TABLE_2));
         tableRepository.save(TABLE_2);
+        TABLE_2_COLUMNS.forEach(column -> column.setTable(TABLE_2));
+        /* create tables 3 */
         TABLE_3.setDatabase(DATABASE_3);
         tableRepository.save(TABLE_3);
-        TABLE_4.setDatabase(DATABASE_2);
-        TABLE_4.setColumns(TABLE_4_COLUMNS);
-        TABLE_4_COLUMNS.forEach(column -> column.setTable(TABLE_4));
-        tableRepository.save(TABLE_4);
-        TABLE_5.setDatabase(DATABASE_2);
-        TABLE_5.setColumns(TABLE_5_COLUMNS);
-        TABLE_5_COLUMNS.forEach(column -> column.setTable(TABLE_5));
-        tableRepository.save(TABLE_5);
+//        TABLE_4.setDatabase(DATABASE_2);
+//        tableRepository.save(TABLE_4);
+//        TABLE_4.setColumns(TABLE_4_COLUMNS);
+//        TABLE_4_COLUMNS.forEach(column -> column.setTable(TABLE_4));
+//        tableRepository.save(TABLE_4);
+//        TABLE_5.setDatabase(DATABASE_2);
+//        tableRepository.save(TABLE_5);
+//        TABLE_5.setColumns(TABLE_5_COLUMNS);
+//        TABLE_5_COLUMNS.forEach(column -> column.setTable(TABLE_5));
+//        tableRepository.save(TABLE_5);
     }
 
     @Test