Question

是否有类似于此的内容：@Insert（onConflict = OnConflictStrategy.REPLACE），可在Room数据库中找到，您可以在Objectbox中执行此操作。如果没有，您如何避免在对象框实体中保存重复的条目？感谢。

Answer 1

private Box<User> userBox;
userBox = ObjectBox.get().boxFor(User.class);

//your inserted object 

if (!userBox.getAll().contains(insertedObject)){
                        leadBoxForLeadOpions.put(l);
                    }

Answer 2

替换对象应该足够简单，只需将@id(assignable=true)注释设置为所需的id字段即可。我已经通过以下方式在我的android应用中对其进行了测试：

@Test
fun testAssignableIdsGetReplaced() {
    val myUser1 = User()
    myUser1.id = 1
    myUser1.nickname = "Original"
    var currentList = boxStore!!.boxFor(User::class.java).all
    assert(currentList.size == 0)
    boxStore!!.boxFor(User::class.java).put(myUser1)
    currentList = boxStore!!.boxFor(User::class.java).all
    assert(currentList.size == 1)
    assert(currentList.get(0).id == 1L)
    val newUser1 = User()
    newUser1.id = 1
    newUser1.nickname = "New"
    boxStore!!.boxFor(User::class.java).put(newUser1)
    currentList = boxStore!!.boxFor(User::class.java).all
    assert(currentList.size == 1)
    assert(currentList.get(0).id == 1L)
    assert(currentList.get(0).nickname == newUser1.nickname)
}

@Entity
class User() {
  @Id(assignable = true) var id: Long = 0
  lateinitvar nickname: String
}

但是请记住，使用ids可分配的注释可能会产生副作用： https://docs.objectbox.io/relations#updating-relations
https://docs.objectbox.io/advanced/object-ids#self-assigned-object-ids

仅在objectbox实体中插入唯一值

2 个答案: