Hello, im having an issue with Kotlin Flow and Room. Im trying to return a Flow of a Tupple data cla...

# android

[Christopher Elías]

Hello, im having an issue with Kotlin Flow and Room. Im trying to return a Flow of a Tupple data class(https://developer.android.com/training/data-storage/room/accessing-data#query-subset-cols). But the compiler throw this error:

WalletDao.java:11: error: Not sure how to convert a Cursor to this method's return type

Has someone experienced something like this?

[gildor]

Could you show how you define your DAO interface

[Christopher Elías]

Sure

@Query("""
    SELECT w.name, w.category_id, w.currency_id, w.amount_now,
    COUNT(money.id) AS movements
    FROM wallet w
    LEFT JOIN money ON w.id = money.parent_id
    WHERE w.id=:walletId
    """)
suspend fun get(walletId: Long): Flow<WalletInformationTuple>

Thats it

[gildor]

Remove suspend

[gildor]

you cannot have suspend + Flow at the same time, and it itself doesn’t make sense, you receive updates when collecting flow, there is no reason to suspend to get this flow

[Christopher Elías]

Andrey Man... Thank you! hahaha I didn't saw the suspend there.

[Aslam Hossin]

I think If we get a warning then might be helpful here.

[gildor]

Error message actually has sense there, it says that there is no adapter for type Flow as return type, the same error message which you receive for any other unknown type as return value.
Of course it may be some special error message just for this case, but it looks a bit artificial. Tho, it may be an IDE lint warning