How would I write a room query over a complex data...

# room

[v79]

How would I write a room query over a complex data type (like LocalDateTime). I'm trying to write a query which would return all events in the last X number of days:

fun getEventsWithin(days: Int): Flow<List<Event>>

I'm really struggling to work out what the SQL would be. The Event entity has a column called dateTime of type LocalDateTime and I have written two @TypeConverter functions which convert between LocalDateTime and Long values.

[v79]

Certainly I can't do it in the @Query() SQL block. (How do @TypeConverters work, anyway? The name of the annotated function seems relevant, I guess it's just doing a compile time check of types?)

[v79]

I've got it working through a `@RawQuery`:

@RawQuery(observedEntities = [Event::class])
    fun getEventsWithin(query: SupportSQLiteQuery): Flow<List<Event>>

And in my repository:

fun getEventsWithin(days: Int): Flow<List<Event>> {
        if(days <= 0) {
            return dao.getAll()
        }
        val now = LocalDateTime.now()
        val xDaysAgo = now.minusDays(days.toLong())
        val xDaysAgoAsLong = xDaysAgo.toEpochSecond(ZoneOffset.UTC)
        return dao.getEventsWithin(SimpleSQLiteQuery("SELECT * FROM Event WHERE dateTime > ? ORDER BY dateTime DESC",
            arrayOf(xDaysAgoAsLong)
        ))
    }

I thought I'd share this because I really couldn't find any examples of this online.