diff --git a/app/src/main/java/phone/vishnu/dialogmusicplayer/MainViewModel.kt b/app/src/main/java/phone/vishnu/dialogmusicplayer/MainViewModel.kt
index c5d272b..8ec7e92 100644
--- a/app/src/main/java/phone/vishnu/dialogmusicplayer/MainViewModel.kt
+++ b/app/src/main/java/phone/vishnu/dialogmusicplayer/MainViewModel.kt
@@ -34,13 +34,13 @@ class MainViewModel(application: Application) : AndroidViewModel(application) {
         this.repository = SaveItemRepository(application)
     }
 
-    fun insert(saveItem: SaveItem?) {
+    fun insert(saveItem: SaveItem) {
         viewModelScope.launch(Dispatchers.IO) {
             repository?.insertSaveItem(saveItem)
         }
     }
 
-    fun delete(saveItem: SaveItem?) {
+    fun delete(saveItem: SaveItem) {
         viewModelScope.launch(Dispatchers.IO) {
             repository?.deleteSaveItem(saveItem)
         }
diff --git a/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemDao.kt b/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemDao.kt
index 959afc3..e04c46a 100644
--- a/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemDao.kt
+++ b/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemDao.kt
@@ -31,16 +31,16 @@ import androidx.room.Update
 interface SaveItemDao {
 
     @Insert(onConflict = OnConflictStrategy.REPLACE)
-    fun insert(saveItem: SaveItem?)
+    fun insert(saveItem: SaveItem)
 
     @Update
-    fun update(saveItem: SaveItem?)
+    fun update(saveItem: SaveItem)
 
     @Delete
-    fun delete(saveItem: SaveItem?)
+    fun delete(saveItem: SaveItem)
 
     @Query("SELECT * FROM SaveItem")
-    fun getAll(): LiveData<List<SaveItem?>>
+    fun getAll(): LiveData<List<SaveItem>>
 
     @Query("DELETE FROM SaveItem")
     fun deleteAll()
diff --git a/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemRepository.kt b/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemRepository.kt
index 0bd6375..f7680cf 100644
--- a/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemRepository.kt
+++ b/app/src/main/java/phone/vishnu/dialogmusicplayer/SaveItemRepository.kt
@@ -33,15 +33,15 @@ class SaveItemRepository(application: Application?) {
         return saveItemDao.getSaveItem(id)
     }
 
-    fun insertSaveItem(saveItem: SaveItem?) {
+    fun insertSaveItem(saveItem: SaveItem) {
         saveItemDao.insert(saveItem)
     }
 
-    suspend fun updateSaveItem(saveItem: SaveItem?) {
+    suspend fun updateSaveItem(saveItem: SaveItem) {
         saveItemDao.update(saveItem)
     }
 
-    fun deleteSaveItem(saveItem: SaveItem?) {
+    fun deleteSaveItem(saveItem: SaveItem) {
         saveItemDao.delete(saveItem)
     }