The query with LIMIT 1 is not emitting updates #5418

yeldar-nurpeissov · 2024-08-25T20:51:01Z

yeldar-nurpeissov
Aug 25, 2024

Version: 2.0.2
Platform: Android

I want to retrieve the oldest row I inserted using the following query:

getOldest:
SELECT *
FROM my_table
ORDER BY createdAt
LIMIT 1;

I use this code to get the result as a flow:

database.myTableQueries.getOldest()
            .asFlow()
            .mapToOne(Dispatchers.Default)

However, it only works during the initial app loading.

To fix this, I use LIMIT 2 and retrieve the first element from the list:

getOldest:
SELECT *
FROM my_table
ORDER BY createdAt
LIMIT 2;

database.myTableQueries.getOldest()
            .asFlow()
            .mapToList(Dispatchers.Default)
            .mapNotNull { it.firstOrNull() }

I’m not sure why the first approach doesn't work, but the second one does.