Can't save longitude in Room database

Question

I've recently encountered an extremly strange proble while developing my simple location based app.

Basically, what I'm trying to achieve is getting LatLng object from OnMapClickListener, saving its latitude and longitude into Room using Dao, and then retrieving them in some other object (fusedLocationProviderClient `s locationCallback to be exact).

Code

Destination - a simple Room Entity which has lat, lng, and timestamp as a primary key.

@Entity(tableName = "destinations")
data class Destination(
        @PrimaryKey var timestamp: Long = 0L,
        var lat: Double = -1.0,
        var long: Double = -1.0
)

DestinationDao - to access Room.

@Dao
interface DestinationDao {

    // Get the newest destination
    @Query("SELECT * FROM destinations WHERE timestamp = (SELECT MAX(timestamp) FROM destinations)")
    fun getDestination(): Destination?

    @Insert(onConflict = OnConflictStrategy.REPLACE)
    fun insertDestination(destination: Destination)
}

MapsActivity - the place where I get coordinates from user click and save them into SQLite using Room

map.setOnMapClickListener { latLng ->
            val destination = Destination(System.nanoTime(), lat = latLng.latitude, long = latLng.longitude)
            
            Log.d(TAG, destination.toString())
            AppDatabase.getInstance(this).destinationDao().insertDestination(destination)
            Log.d(TAG, AppDatabase.getInstance(this).destinationDao().getDestination().toString())
        }

MyLocationListener - the place where I retrieve my coordinates from Room

private val locationCallback = object : LocationCallback() {
        override fun onLocationResult(userLocation: LocationResult?) {
            val array = FloatArray(1)
            val destination = AppDatabase.getInstance(appContext).destinationDao().getDestination()

            Log.d(TAG, "Distance: ${array[0]} m\nlat: ${destination!!.lat}, long: ${destination.long}")
        }
    }

The problem

It seems simple, but for an unknown reason, longitude never gets saved to Room! To better illustrate this, here are the logs from that MapsActivity snippet (-1.0 is a default value)

// Destination created from `LatLng` object from map click listener
D/MapsActivity: Destination(timestamp=248767407310345, lat=50.1813350498603, long=18.45104455947876)
// Destination retrieved from  Room
D/MapsActivity: Destination(timestamp=248767407310345, lat=50.1813350498603, long=-1.0)

I have completely no idea why is that. I tried changing Double to String and then parsing it, tried reducing the count of decimal places, I even tried changing the order of variables declaration in Destination class - nothing works.

If any additional data is needed, I'll post it. Thank you in advance.

Answer 1

It may be so, because you called you longitude variable - long! "Long" is reserved word in Java, not in Kotlin, I know, but, what if you try to change this row:

var long: Double = -1.0

to

var longitude: Double = -1.0