Kotlin上的Room Database有什么问题？

Question

I have a data class

@Entity(tableName = "type")
data class Type(
    @PrimaryKey(autoGenerate = true) var id: Int = 0,
    var type: Int = 0
)

When compiling project I receive message

Error:Room cannot pick a constructor since multiple constructors are suitable.

But if I change data class to

@Entity(tableName = "type")
data class Type(
    @PrimaryKey(autoGenerate = true) var id: Int = 0,
    var type: String = ""
)

or java class

@Entity(tableName = "type")
public class Type {
    @PrimaryKey(autoGenerate = true)
    private int id;
    private int type;
    // getters and setters
}

it works fine. Is it Kotlin bug or something else?

Answer 1

I do not know why this occurs, but if you use id? = 0 solves the problem, at least in the tests I did.

Android Studio Beta 7
ext.support_version = '26 .1.0 '
ext.kotlin_version = '1.1.51'
ext.anko_version = '0.10.1'
ext.archroom_version = '1.0.0-alpha9-1'

    @Entity(tableName = "type")
    data class Type(
            @PrimaryKey(autoGenerate = true) var id: Int? = 0,
            var type: Int = 0
    )