android room query returns null
I've been looking at Room query examples but haven't been able to fix the issue. I don't see any bugs when I run the code except a null pointer exception when I ... , Your setId method does not reference the field id . Your parameter shadows your field. I think you should be using this.id instead., The value of the Livedata (dao.getLotto(gameNum).value) might be null, but the instance of Livedata will not be null. Its something like ..., EDIT As @pskink pointed out in the comments, the problem is the query. The problem lies in the query: @Override public ...,If a Single<T> query returns null , Room will throw EmptyResultSetException . Additionally if the statement is an INSERT, UPDATE or DELETE then the return types ... , If a Single<T> query returns null , Room will throw EmptyResultSetException . UPDATE or DELETE queries can return void or int . If it is an int , the value is the number of rows affected by this query.,From Android Developers documentation: LiveData is a data holder class that can be observed within a given lifecycle. which means you will have to register an ... , Your Query returns a LiveData . You will have to observe the changes. Initially, the value is null before the query. After the query, the list dataset ..., Room query with ID returns null · android android-room. I am using Room Persistance Library for my database. One of my queries returns null ..., That's because it's probably querying the database when its empty. so the best way to solve this is to return a LiveData instead of a primitive int.
| 相關軟體 SQLite 資訊 | |
|---|---|
 android room query returns null 相關參考資料
android - Room query returns null - Stack Overflow
I've been looking at Room query examples but haven't been able to fix the issue. I don't see any bugs when I run the code except a null pointer exception when I ... https://stackoverflow.com Android room persistence query is returning null value - Stack ...
Your setId method does not reference the field id . Your parameter shadows your field. I think you should be using this.id instead. https://stackoverflow.com Android Room Query never return null? - Stack Overflow
The value of the Livedata (dao.getLotto(gameNum).value) might be null, but the instance of Livedata will not be null. Its something like ... https://stackoverflow.com Android Room: Query returns null in inherited field - Stack ...
EDIT As @pskink pointed out in the comments, the problem is the query. The problem lies in the query: @Override public ... https://stackoverflow.com androidx.room.Query - Query | Android Developers
If a Single<T> query returns null , Room will throw EmptyResultSetException . Additionally if the statement is an INSERT, UPDATE or DELETE then the return types ... https://developer.android.com Query | Android Developers
If a Single<T> query returns null , Room will throw EmptyResultSetException . UPDATE or DELETE queries can return void or int . If it is an int , the value is the number of rows affected by thi... https://developer.android.com Room query returns null - Stack Overflow
From Android Developers documentation: LiveData is a data holder class that can be observed within a given lifecycle. which means you will have to register an ... https://stackoverflow.com Room query returns null value - Stack Overflow
Your Query returns a LiveData . You will have to observe the changes. Initially, the value is null before the query. After the query, the list dataset ... https://stackoverflow.com Room query with ID returns null - Stack Overflow
Room query with ID returns null · android android-room. I am using Room Persistance Library for my database. One of my queries returns null ... https://stackoverflow.com Room. The first query returns null value - Stack Overflow
That's because it's probably querying the database when its empty. so the best way to solve this is to return a LiveData instead of a primitive int. https://stackoverflow.com |