IssueTracker

Component used: Android Room

Version used: 2.7.0

Devices/Android versions reproduced on: Pixel 4 API 31 Emulator (same on any physical device)

Hi team, after updating Room from 2.6.1 to 2.7.0 I have noticed that my app changed behavior when fetching data from db. After investigation it turned out that starting with version 2.7.0 there seems to be an internal change (bug?) on how Room resolves ambiguity with same named columns when using inner join. Here is the most simple example from my codebase:

  @Query(
    "SELECT movies.*, movies_see_later.created_at, movies_see_later.updated_at FROM movies " +
      "INNER JOIN movies_see_later USING(id_trakt)",
  )
  override suspend fun getAll(): List<Movie>

"Movie" entity contains:

@Entity(tableName = "movies")
data class Movie(
  ...
  @ColumnInfo(name = "updated_at") val updatedAt: Long,
  @ColumnInfo(name = "created_at") val createdAt: Long,
)

@Entity(
  tableName = "movies_see_later",
  ...
)
data class WatchlistMovie(
  ...
  @ColumnInfo(name = "created_at") val createdAt: Long,
  @ColumnInfo(name = "updated_at") val updatedAt: Long,
)

Before 2.7.0, for Movie list result, these fields were mapped from movies_see_later.created_at and movies_see_later.updated_at - as I want them to be. After 2.7.0 it seems like this is no longer a case.

I am not sure if this is an issue introduced in 2.7.0 or actual fix to how Room is handling this now. I have not seen anything about it in 2.7.0 release note.

Regards!