IssueTracker

Sorry, the fix for this issue is in Room 2.5.0 and not 2.4.x, we are working on getting a stable release of 2.5.0 soon.

Room 2.5.0-rc01 was recently released, the next release will be 2.5.0. Unfortunately the US holidays are around the corner and the next androidx release will be early next year.

Room 2.5.1, this issue still exists when selecting using a join to filter data but omitting the joined data in the result. E.g. when Entity1 has column named id and Entity2 also has id, and I use a @Query that returns a List<Entity1> with a simple join in order to filter only those of Entity1 who have a relation to certain Entity2. The resulting List<Entity1> contains instances of Entity1 whose ids are wrongly assigned to those of their respective joined Entity2. And that is regardless whether @RewriteQueriesToDropUnusedColumns is being used or not.

#8, can you provide a sample app that reproduces that error? Seeing the query + entity1/2 should be enough. thanks.

I'm also still seeing this issue in Room 2.6.0. I'm able to produce it using the query from the "Query multiple tables" example.

@Query(
    "SELECT * FROM book " +
    "INNER JOIN loan ON loan.book_id = book.id " +
    "INNER JOIN user ON user.id = loan.user_id " +
    "WHERE user.name LIKE :userName"
)
fun findBooksBorrowedByNameSync(userName: String): List<Book>

I created these entities to go with it:

@Entity
data class Book(
    @PrimaryKey(autoGenerate = true) val id: Int,
    val title: String,
)

@Entity
data class Loan(
    @PrimaryKey(autoGenerate = true) val id: Int,
    @ColumnInfo(name = "book_id") val bookId: Int,
    @ColumnInfo(name = "user_id") val userId: Int,
)

@Entity
data class User(
    @PrimaryKey(autoGenerate = true) val id: Int,
    val name: String,
)

When testing it with this

@Test
    fun returnsCorrectIds() {
        val users = (1..5).map { User(id = 0, name = "User $it") }
        userDao.insert(users)
        val books = (1..5).map { Book(id = 0, title = "Book $it") }
        bookDao.insert(books)
        val insertedBooks = bookDao.getAll()
        assertThat(insertedBooks).contains(Book(id = 4, title = "Book 4")) // Book 4 has id 4
        loanDao.insert(Loan(id = 0, bookId = 4, userId = 2))
        val borrowedBooks = bookDao.findBooksBorrowedByNameSync("User 2")
        assertThat(borrowedBooks).containsExactly(Book(id = 4, title = "Book 4"))
    }

the last assertion here fails:

value of: iterable.onlyElement()
expected: Book(id=4, title=Book 4)
but was : Book(id=2, title=Book 4)

So the Books that are returned all have the User's ID in the id field. (If Book had name instead of a title it would also return the User's name as the Book's name.) If I change the order of the two joins, then the returned Books have the ID of the Loan.