diff --git a/GBDaoGenerator/src/nodomain/freeyourgadget/gadgetbridge/daogen/GBDaoGenerator.java b/GBDaoGenerator/src/nodomain/freeyourgadget/gadgetbridge/daogen/GBDaoGenerator.java
index 44d3957c..499ebc0a 100644
--- a/GBDaoGenerator/src/nodomain/freeyourgadget/gadgetbridge/daogen/GBDaoGenerator.java
+++ b/GBDaoGenerator/src/nodomain/freeyourgadget/gadgetbridge/daogen/GBDaoGenerator.java
@@ -63,7 +63,7 @@ public class GBDaoGenerator {
         tag.addIdProperty();
         tag.addStringProperty("name").notNull();
         tag.addStringProperty("description").javaDocGetterAndSetter("An optional description of this tag.");
-        tag.addLongProperty("userId");
+        tag.addLongProperty("userId").notNull();
 
         return tag;
     }
@@ -128,8 +128,8 @@ public class GBDaoGenerator {
     }
 
     private static void addDateValidityTo(Entity entity) {
-        entity.addDateProperty(VALID_FROM_UTC);
-        entity.addDateProperty(VALID_TO_UTC);
+        entity.addDateProperty(VALID_FROM_UTC).codeBeforeGetter(OVERRIDE);
+        entity.addDateProperty(VALID_TO_UTC).codeBeforeGetter(OVERRIDE);
 
         entity.implementsInterface(VALID_BY_DATE);
     }
@@ -189,10 +189,10 @@ public class GBDaoGenerator {
         activityOverlay.addIntProperty(TIMESTAMP_FROM).notNull().primaryKey();
         activityOverlay.addIntProperty(TIMESTAMP_TO).notNull().primaryKey();
         activityOverlay.addIntProperty(SAMPLE_RAW_KIND).notNull().primaryKey();
-        Property deviceId = activityOverlay.addLongProperty("deviceId").primaryKey().getProperty();
+        Property deviceId = activityOverlay.addLongProperty("deviceId").primaryKey().notNull().getProperty();
         activityOverlay.addToOne(device, deviceId);
 
-        Property userId = activityOverlay.addLongProperty("userId").getProperty();
+        Property userId = activityOverlay.addLongProperty("userId").notNull().getProperty();
         activityOverlay.addToOne(user, userId);
         activityOverlay.addByteArrayProperty("rawPebbleHealthData");
 
@@ -221,9 +221,9 @@ public class GBDaoGenerator {
                         "intensity, are device specific. Normalized values can be retrieved through the\n" +
                         "corresponding {@link SampleProvider}.");
         activitySample.addIntProperty("timestamp").notNull().codeBeforeGetterAndSetter(OVERRIDE).primaryKey();
-        Property deviceId = activitySample.addLongProperty("deviceId").primaryKey().codeBeforeGetterAndSetter(OVERRIDE).getProperty();
+        Property deviceId = activitySample.addLongProperty("deviceId").primaryKey().notNull().codeBeforeGetterAndSetter(OVERRIDE).getProperty();
         activitySample.addToOne(device, deviceId);
-        Property userId = activitySample.addLongProperty("userId").codeBeforeGetterAndSetter(OVERRIDE).getProperty();
+        Property userId = activitySample.addLongProperty("userId").notNull().codeBeforeGetterAndSetter(OVERRIDE).getProperty();
         activitySample.addToOne(user, userId);
     }
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/database/DBHelper.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/database/DBHelper.java
index 2466a675..51dfff4c 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/database/DBHelper.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/database/DBHelper.java
@@ -605,8 +605,8 @@ public class DBHelper {
             int colSteps = cursor.getColumnIndex(KEY_STEPS);
             int colType = cursor.getColumnIndex(KEY_TYPE);
             int colCustomShort = cursor.getColumnIndex(KEY_CUSTOM_SHORT);
-            Long deviceId = DBHelper.getDevice(targetDevice, targetSession).getId();
-            Long userId = user.getId();
+            long deviceId = DBHelper.getDevice(targetDevice, targetSession).getId();
+            long userId = user.getId();
             newSamples = new ArrayList<>(Math.min(BATCH_SIZE, cursor.getCount()));
             while (cursor.moveToNext()) {
                 T newSample = sampleProvider.createActivitySample();
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/entities/AbstractActivitySample.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/entities/AbstractActivitySample.java
index 77ec7508..06718116 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/entities/AbstractActivitySample.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/entities/AbstractActivitySample.java
@@ -42,7 +42,7 @@ public abstract class AbstractActivitySample implements ActivitySample {
 
     public abstract void setTimestamp(int timestamp);
 
-    public abstract void setUserId(Long userId);
+    public abstract void setUserId(long userId);
 
     @Override
     public void setHeartRate(int heartRate) {
@@ -53,11 +53,11 @@ public abstract class AbstractActivitySample implements ActivitySample {
         return NOT_MEASURED;
     }
 
-    public abstract void setDeviceId(Long deviceId);
+    public abstract void setDeviceId(long deviceId);
 
-    public abstract Long getDeviceId();
+    public abstract long getDeviceId();
 
-    public abstract Long getUserId();
+    public abstract long getUserId();
 
     @Override
     public int getRawIntensity() {