Android Room map sub select result to a non column parameter

Question

我有

@Entity
public class Tag {
@PrimaryKey(autoGenerate = true)
private long id;
@ColumnInfo(name = "name")
private String name;
@Ignore
private int totalRecords;
}

和

@Query("SELECT *) FROM Tags ORDER BY importance DESC, name ASC")
LiveData<List<Tag>> getAll();

我想 select 计数来自花药 table 的标签并将其映射到 'totalRecords' 所以，我的查询变成了

@Query("SELECT *, (SELECT count(id) from RecordingAndTags where tagId=t.id) as totalRecords FROM Tags t ORDER BY importance DESC, name ASC")
LiveData<List<Tag>> getAll();

您可能已经猜到它失败了

The query returns some columns [totalRecords] which are not use by com.myapp.entities.Tag. You can use @ColumnInfo annotation on the fields to specify the mapping.

所以我已经将我的 'totalRecords' 修改为

@ColumnInfo(name = "totalRecords")
@Ignore
private int totalRecords;

不幸的是，它也没有用，并因同样的警告而失败。

我错过了什么吗？我做不到吗？

Answer 1

这似乎不再是 1.1.0-beta2

的问题

Android Room map sub select result to a non column parameter

Android Room map sub select result to a non column parameter

sqlite

android-room

android-livedata