Andorid房间2个primaryKeys，1个autoGenerate

Question

我想有两个主键，其中一个应该是自动生成的，我试着这样做：

@Entity(tableName = "object_to_group"，primaryKeys = {"id“，"object_id"}，)公共类ObjectsToGroup {

@ColumnInfo(name = "id",autoGenerate = true)
public long id;

但是编译器显示了错误

当我这样做的时候：

@PrimaryKey(autoGenerate = true)
@ColumnInfo(name = "id")
public long id;

一个编译器告诉我错误，我应该怎么做？

Answer 1

使用复合主键无法添加自动增量。作为另一种选择，您可以使用唯一索引。例如

@Entity(tableName = "object_to_group", indices = {@Index(value = 
       {"object_id"}, unique = true)})
public class ObjectsToGroup {

    @PrimaryKey(autoGenerate = true)
    private int id;

    @ColumnInfo(name = "object_id")
    private int object_id;
}