Fix lob errors

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/DeviceRepository.java

@@ -6,6 +6,8 @@ import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.query.Param;
 
+import javax.transaction.Transactional;
+
 /**
  * DeviceRepository acts as a superclass for the other repositories so to mirror in the database the
  * class inheritance present among the various devices.
@@ -20,6 +22,7 @@ public interface DeviceRepository<T extends Device> extends CrudRepository<T, Lo
      * @param username a User's username
      * @return an optional device, empty if none found
      */
+    @Transactional
     @Query("SELECT d FROM Device d JOIN d.room r JOIN r.user u WHERE d.id = ?1 AND u.username = ?2")
     Optional<T> findByIdAndUsername(Long id, String username);
 
@@ -29,6 +32,7 @@ public interface DeviceRepository<T extends Device> extends CrudRepository<T, Lo
      * @param username the User's username
      * @return all devices of that user
      */
+    @Transactional
     @Query("SELECT d FROM Device d JOIN d.room r JOIN r.user u WHERE u.username = ?1")
     List<T> findAllByUsername(String username);
 
@@ -38,6 +42,7 @@ public interface DeviceRepository<T extends Device> extends CrudRepository<T, Lo
      * @param deviceId the device id
      * @return a user object
      */
+    @Transactional
     @Query("SELECT u FROM Device d JOIN d.room r JOIN r.user u WHERE d.id = ?1")
     User findUser(Long deviceId);
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Room.java

@@ -125,7 +125,6 @@ public class Room {
      * https://www.baeldung.com/java-base64-image-string
      * https://docs.oracle.com/javase/8/docs/api/java/util/Base64.html
      */
-    @Lob
     @Column(name = "image", columnDefinition = "TEXT")
     private String image;